CN86204294U

CN86204294U - Tachometrical apparatus with microprocessor for rotating machinery

Info

Publication number: CN86204294U
Application number: CN 86204294
Authority: CN
Inventors: 俞道法
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-06-21
Filing date: 1986-06-21
Publication date: 1987-05-27

Abstract

The utility model relates to a test instrument with a microprocessor for testing the rotational speed of the machinery, comprising Z80CPU, CTG, EPROM, RAM and some digital elements. The utility model is matched with a contactless infrared sensing element, tests the revolutions per minute for the rotary machine, and is used as the real-time clock. As the utility model adopts the microprocessor real-time trace treatment counting mode on the revolution speed signal, the measurement precision is high. The utility model has the advantages of high precision, small size, light weight, low cost, less power consumption and wide purpose, is especially suitable for matching with the mechanical equipment of the rotation class, tests the revolution speed, and controls the working conditions of various electric motors.

Description

Tachometrical apparatus with microprocessor for rotating machinery

The utility model belongs to the electronic test instrument of test rotating machinery velocity of rotation.

The mechanical separator speed electronic test instrument is that some mechanical rotation body velocity of rotation of test is the instrument of rotations per minute.Divide analog and digital two kinds.Digital measurement of rotating speed instrument is generally by corner---and pulses switch part and digital counting, demonstration two parts are formed.Existing technology is: adopt certain way corner---pulse converter and mechanical rotation sports association are connected together, and itself and rotary body are rotated synchronously.Corner---pulse converter whenever revolves and turns around, and just produces corresponding electric impulse signal.The electric pulse number that digital counting, display part record are produced, after the processing that suitably converts, shown numeral is promptly represented the rotating speed of rotary body.Common corner---pulses switch mode has modes such as magneto-electric, Hall element formula, Gao Pin Zhen Swing formula, electrostatic capacity type, photo-electric.Digital counting, display part generally include pulse amplification, shaping, counting circuit and digital display circuit etc.In fields such as engineering, production, experiment, various rotation class mechanical separator speed testers have been made according to above-mentioned technology, in order to test the rotating speed of various rotary machines such as vehicle, lathe, motor etc.These test instrumentations in conversion efficiency, measuring accuracy, environment temperature requirement, miniaturization, the aspect such as install and fix, also need to innovate technologies.

The utility model is intended to adopt advanced contactless infrared sensing mode and microcomputer technology, adopts real-time follow-up to handle counting mode to measured signal, to substitute general rotating machinery measurement of rotating speed instrument.This tester and various rotation class mechanical equipment coordinations both can be made real time clock, accurately showed the time, can show the rotary machine rotations per minute again.

Infrared ray resolution height more can adapt to weather effect than visible light, in atmosphere scattering less, no matter by day, night, can both accurately receive.In recent years, obtained at aspects such as military affairs, industrial and agricultural production, medical science, scientific researches using widely.Corner of the present utility model---pulses switch part is by miniwatt infrared emitter, pyroscan and have circular hole or the dish that is in the light of breach is formed.Digital counting, display part then mainly are made up of RAM and the EPROM of 2K, six eight hop count sign indicating number displays of Z80CPU, CTC, 1K.All program and data all are solidificated among the 2KEPROM, after the start, and under the CPU unified management, the follow procedure number of winning the confidence automatically, conversion, counting, demonstration, self check, timing.The revolution that shows real-time time or rotating machinery per minute by the control of outer button switch.

The dish that is in the light that has circular hole or breach is fixed on the tested rotary body, rotates with tested rotary body.Infrared emitter and detector are positioned at the both sides of the dish that is in the light.When the circular hole on the dish that is in the light or breach and radiation source, detector were in the straight line position, detector detected infrared radiation signal.The mechanical rotation body whenever rotates a circle, and infrared eye just once receives the chance of infrared radiation, represents that promptly rotary body rotates a week.

Rotary body also often has vibration when normal rotation, thereby produces dither signal, introduces and disturbs, and causes test error.The utility model adopts microcomputer real-time follow-up processing mode to the counting of rotating speed.Concrete processing procedure is: under the CPU unified command, realize by CTC and query window.In a single day the passage receiving end of CTC receives tacho-pulse, promptly interrupts to the CPU application, and CPU receives application, this passage that resets, and data cycle length of once rotating before taking out from the deposit data district simultaneously divided by a constant, form the shielding time.Change CTC shielding passage at the beginning, by time this moment regularly, as long as the shielding time of selecting pass the circular hole on the dish that is in the light or the time of breach greater than infrared radiation, then owing to the malfunction signal that mechanical shaking produces must not enter the CTC counting channel.After shielding was timed to preset time, the shielding passage interrupted to the CPU application.CPU receives interruption, and by query window, inquiry tach signal input end confirms that this tach signal really finishes, and then the rotating speed counting increases 1.Also do not disappear if inquire this tach signal, then shield passage always.The diameter that the dish that is in the light is gone up circular hole or breach is more little, and the scope of shielding time is then big more.Because counting carries out after shielding is regularly finished, and therefore can thoroughly solve the miscount that causes owing to mechanical vibration.

The utility model cpu clock produces by crystal oscillator.According to the scope that tracking velocity, degree of accuracy required and tested rotating speed, can select the suitable Jing Ti Zhen Swing frequency and the Z80CPU chip of relevant work frequency.

Test result shows with the per minute integrating tachometer, so sub-signal or claim that timing signal is the benchmark of test rotating speed.The utility model is directly selected CTC timer sub-signal for use, guarantees measuring accuracy.

Timing is another critical function of this tester.Real time clock signal second directly with crystal oscillator by CTC regularly, produces by integral multiple.Because the degree of stability of crystal oscillator is 10 ^-7More than, so the accuracy of timekeeping height.

Accompanying drawing is a microcomputer rotation class mechanical separator speed tester theory diagram.

Among the figure, the 1st, miniwatt semiconductor infrared origin; The 2nd, miniwatt semiconductor infrared eye; The 3rd, have the dish that is in the light of circular hole or breach 13, the dish that is in the light rotates synchronously with mechanical rotary body, and infrared eye receives radiation signal, presents low-resistance, chooses suitable resistance, and for example 30K Ω forms the negative pulse tach signal; The 4th, pulse shaping circuit; The 5th, query window, such as, can select ternary output eight impact damper 74LS244 for use.The passage of query window and CTC receives the negative pulse tach signal simultaneously; The 6th, this instrument cpu clock generator circuit; The 7th, decoding of this instrument and control circuit; 10,8 is respectively digital video data latch and driver; 11,9 is respectively digital position control latch and the driver of showing; 18 is six eight hop count sign indicating number displays, and when showing respectively, minute, second or rotations per minute, going to 999999 from per minute 1 changes; The 12nd, address of the present utility model, data, control bus; The 14th, switch is controlled timing or measurement of rotating speed respectively, also produces the self-correcting signal in the time of the instrument timing; The 15th, switch, control instrument is tested oneself or self-correcting respectively.Self-checking function has been simplified instrument making, debug process, brings convenience for use, maintenance; 16, the 17th, the real time clock timing, transfer to divide a calibration button, whenever press once, in the time of then or branch increase 1.

The utility model is owing to adopt microcomputer chip and distinctive real-time follow-up is handled counting mode, and simple in structure, easy to operate, stable performance, reliable, the used element of test is few, cost is low, in light weight, little power consumption.By testing the rotating speed of rotating machinerys such as various motor vehicles, tractor, tank, aircraft, ship, lathe, can in time understand the working condition of engine, also can make operating personnel grasp real-time time accurately simultaneously, therefore of many uses.

Claims

1, a kind of rotation class mechanical separator speed tester, form by corner-pulses switch and digital counting, demonstration two parts, it is characterized in that corner-pulses switch partly adopts contactless infrared sensor, digital counting, display part mainly are made up of Z80CPU, CTC, EPROM, RAM, nixie display.

2, according to the described rotation class of claim 1. mechanical separator speed tester, it is characterized in that adopting the contactless infrared sensor of semiconductor infrared origin, infrared eye.

3, according to the described rotation class of claim 1. mechanical separator speed tester, it is characterized in that, adopt the microcomputer real-time follow-up to handle counting mode tested tach signal by CTC and query window.

4, according to the described rotation class of claim 1. mechanical separator speed tester, it is characterized in that two positions, can control demonstration real-time time or rotating speed respectively by a switch.