CN86205794U

CN86205794U - Measuring insturment for rotating speed stability

Info

Publication number: CN86205794U
Application number: CN 86205794
Authority: CN
Inventors: 余承业; 廖日平; 王玲
Original assignee: ELECTRONICS INST HENGYANG CITY HUNAN PROV
Current assignee: ELECTRONICS INST HENGYANG CITY HUNAN PROV
Priority date: 1986-08-09
Filing date: 1986-08-09
Publication date: 1987-09-12

Abstract

The utility model relates to an instrument with a microcomputer, which is used for measuring the stable degree of a rotary speed, an average rotary speed, and an instantaneous rotary speed. The utility model is especially suitable for the power machinery of a diesel engine, a gasoline engine, etc., and uses a computer to carry out sampling and measuring the rotary speed of machinery and the period of a pulse. The instantaneous rotary speed and the absolute deviation valve of the rotary speed are obtained by reverse calculation, and are displayed, printed, and recorded. The block diagram of the utility model is as above (omitting).

Description

Measuring insturment for rotating speed stability

The utility model is about power machine, particularly the surveying instrument of diesel engine, petrol engine rotational speed degree of stability.

When power machine operates in a certain rotating speed, owing to multiple reason, can absolute stability on this rotating speed, but in the certain up and down scope of this rotating speed, fluctuate, be commonly called as tourist bus.Measure the maximal value and the minimum value of the actual speed of its this moment, obtain its difference, be called the rotating speed absolute error, the ratio between absolute error and the mean speed is a relative error.The instrument that this difference of current measurement is used mostly is the mechanical type tachometer gage, and range estimation beat of pointer amplitude is read the change in rotational speed difference.But it is very big that the low precision of this measuring method, measurement result are influenced by operator's subjective factor.Use digital tachometer, the rotating speed that records is a mean value, can not measure the change in rotational speed difference.The utility model just provides a kind of instrument of measuring the power machine rotating stability, also can be used for the measurement of the degree of stability of other frequency aspect.

The utility model is that mechanical separator speed is passed through rotating speed---impulse transfer device variable speed is the pulse train that a frequency is directly proportional with it.Back input microcomputer is amplified in this pulse train shaping, in measuring power machine rotating stability official hour (for example three minutes or five minutes), by the Controlled by Microcomputer continuous sampling pulse train in the instrument, the length of the recurrence interval that continuous coverage goes out to be sampled.Find out maximal value and the minimum value of recurrence interval by microcomputer, their are minimum speed and maximum (top) speed of corresponding machinery respectively, draws absolute error value and relative error value after the computing, is shown and printer prints is noted by charactron.

The utility model also is provided with a function selecting button switch, the usefulness of available measurement mean speed, absolute error, relative error and transient speed.

Fig. 1 is the functional-block diagram of the utility model instrument.

Fig. 2 is the sequential chart of the utility model instrument signal.

Fig. 3 is the computer applied algorithm block diagram.

Fig. 4 is an embodiment of utility model.

Select Fig. 1 accompanying drawing of book extract as an illustration.

Describe with reference to the accompanying drawings below.

Among Fig. 1, the rotating speed V(of power machine rev/min) pass through rotating speed---the pulse train that the impulse transfer device becomes a frequency to be directly proportional with it to transformation of speed, guarantee its scale-up factor by converting means.If the cycle of this pulse train is TX, frequency is fX, and back input microcomputer is amplified in this pulse train shaping.

Among Fig. 2,1 is the pulse train waveform after the shaping amplification; 2 is the period T xi waveform of computer sampling to i pulse; 3 is the timing pulse of the sampling timing of computing machine generation itself, as the time measure unit of Txi; 4 is when measuring 1 second door of rotating speed.

If the maximum cycle of the pulse that samples is Txmax, the minimum period is Txmin.F then _Xmax=1/ (Txmin), f _Xmin=1/ (Txmax), then the absolute error of maximum (top) speed and minimum speed is △ V=f _Xmax-f _Xmin, mean speed is V, relative deviation is δ=(△ V)/(V) %.

In the process of measuring, the computing machine Txi value of constantly sampling samples the Txmax, the Txmin value that are retained in the internal storage location with the front and compares.If Txi＞Txamx then sends into the Txi value in the internal storage location of preserving Txmax and preserves; If Txi＜Txmix, then Txi value is sent in the internal storage location of preservation Txmin and stored.Can record maximal value and the minimum value of the Txi in the Measuring Time of regulation like this.Ask to have bad luck to calculate by computing machine and obtain fxmax value and fxmin value, △ V=f so _Xmax-f _XminInstrument is with △ V value and δ=(△ V)/(V) % value shows and print record is got off.The program of computing machine is worked out with regard to principle according to this.

In Fig. 4 embodiment, mechanical separator speed is transformed to pulse train and is realized by electromagnetic induction transducer (11).(5) be 8748 single chip microcomputers.The INT end input of back by 8748 single-chip microcomputers amplified in the pulse train shaping, and as the read signal that interrupts, 2,3 terminations of 8748 single-chip microcomputers have the clock of crystal oscillator (10) as computing machine.AN1 is the function selecting button switch, is connected to the T of 8748 single-chip microcomputers ₀End can supply mean speed V, absolute error △ V, relative error With four kinds of usefulness of measuring selection of transient speed V.P _FD～P ₂₇Be 8748 single machine output end.(6) be integrated circuit 4511, it is seven sections decoding display drivers.(7) be seven segment digital tubes.Four input ends of 4511 are connected to 8748 P respectively ₁₀～P ₁₃, output terminal a～g is in parallel as word line output control with four seven segment digital tubes respectively.8748 P ₁₄～P ₁₇Be connected with the public pole of four seven segment digital tubes respectively by 75492 drivers (8), as bit line output control.8748 P ₂₄～P ₂₇Output port through 75492 drivers (8) be connected to respectively with after four light emitting diodes (9) and current-limiting resistance thereof are connected+the 5V power supply uses as function selecting indication.AN2 is 8748 rest button, and measurement result is shown by seven segment digital tubes (7) and printer (10) print record is got off.

Claims

1, rotating stability measuring instrument is that the transformation of speed with power machine is a pulse train, and cycle, the frequency values of measuring this pulse train draws power machine rotating speed and rotating speed deviation.The utility model instrument is characterised in that, microsystem by eight microcomputers (5) commonly used and its application program formation, seven sections decoder drivers (6), seven segment digital tubes (7), driver (8), light emitting diode (9) and current-limiting resistance thereof, function selecting button switch AN1, printer (10) is formed.The characteristics of computer applied algorithm establishment are to draw instantaneous frequency fxi behind the instantaneous period T xi, Computing of continuous sampling and continuous coverage pulse train, promptly corresponding transient speed v.At any time keep the maximum (top) speed value vmax and the minimum speed value vmin that obtain after the computing, again through the absolute error value Δ v that obtains rotating speed after the computing and relative error value δ, these values are selected to send into seven segment digital tubes show to reach and note by printer prints.

2, rotating stability measuring instrument according to claim 1 is characterized in that the microcomputer that adopts can be Z80 series, or the MCS-48 series monolithic, the MCS-51 series monolithic.