CN107782268A

CN107782268A - A kind of inner eccentric holes detecting system

Info

Publication number: CN107782268A
Application number: CN201610715329.5A
Authority: CN
Inventors: 郭琳
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-08-25
Filing date: 2016-08-25
Publication date: 2018-03-09

Abstract

The degree of eccentricity in deep hole machining is to weigh an important indicator of deep hole machining quality, detected point by point for existing craft, the shortcomings that detection speed is slow, ultrasonic thickness measurement system that can not be to body complete detection, by central inventive of C805lF340 single-chip microcomputers, a kind of inner eccentric holes detecting system is made up of two big modules,, the complete detection of automation continuous to workpiece to be machined real-time online is realized, so as to improve the efficiency and precision that deep hole adds Z.Experiment shows stable system performance, and precision is high, has broad application prospects.

Description

A kind of inner eccentric holes detecting system

Art

The present invention relates to a kind of detection means, more particularly to a kind of inner eccentric holes detecting system.

Background technology

In modern mechanical industry, deep hole machine tooling is processed maximum different in operational control from general stock-removing machine Part is that deep hole machining is carried out under the shelter condition that operator can not directly observe with vision, and deep hole drill breaks Whether bits, chip removal, the abrasion of cutting edge, Chip Morphology, surface to be machined situation are correct etc. down to drill bit trend, are all to determine to add Work success or failure, quality, the significant impact factor of efficiency and cost, but these all with the naked eye can not directly perceive.Pass through real-time online The change of its offset is measured, its production efficiency can be improved, for applied to industrial production line, ultrasonic thickness measurement is fortune With a kind of most commonly used method.

Ultrasonic wave is as caused by mechanical oscillation, can be propagated at different rates in different medium, have directionality it is good, Energy is concentrated, is decayed the advantages that smaller, albedo is stronger in transmitting procedure.Ultrasonic thickness measurement technology is divided into resonant mode from principle With 2 kinds of pulse reflection.System uses pulse reflection thickness measuring method, and its principle is：After ultrasonic wave enters people's measured material, expect surveying Top and bottom between roundtrip formed multiple reflection.If can measure ultrasonic wave in the material the propagation of round trip when Between △ t, can be in the hope of thickness d=v/ △ t of measured material in the case of known to speed v.

The content of the invention

The purpose of the present invention be detected point by point for existing craft, detection speed is slow, body complete detection can not be surpassed The shortcomings that sound thickness measuring system, devise a kind of inner eccentric holes detecting system.

The technical solution adopted for the present invention to solve the technical problems is.

Inner eccentric holes detecting system is made up of two big modules, i.e. ultrasound emission receiving circuit part and single chip part.It is super Acoustic emission receiving circuit part receives amplifying circuit, adjustable gain amplification demodulatoring circuit, door electricity by system power supply module, transmitting Road etc. forms.System uses pulse reflection thickness measuring method, and probe is using water immersion focusing compressional wave normal probe detection wall thickness.Radiating circuit One rise time of output is very short, the very narrow periodicity electric pulse of pulse, is added to by cable on probe, excitation piezoelectric chip production Raw ultrasonic pulse.After the ultrasonic pulse sent of popping one's head in enters workpiece, multiple reflections are formed on two surfaces up and down of workpiece.Reflection Ripple is through piezoelectric chip reconvert into electric signal.After received circuit amplification, sound wave is measured in workpiece two by time difference extraction circuit Propagation time t between individual surface, so as to obtain the thickness of workpiece.

The radiating circuit of described ultrasonic wave is under transmitting burst pulse control, produces the high voltage-controlled of excitation ultrasonic probe Signal processed, it is achieved thereby that ultrasonic wave is launched.

Using 600 V high-pressure modular in described system, IRF840 is a N-channel enhanced power field-effect Pipe, resistance to 600V high pressure, conducting resistance are small.

Described ultrasonic wave receiving circuit is by low noise pre-amplification circuit, VCA810 variable-gain amplification circuits, detection Circuit and gate control circuit composition.

Described variable-gain amplification circuit is using high-gain, low noise, low distortion, the pressure of control range continuously adjustabe Amplifier VCA810 is controlled to complete.

Described detecting circuit is made up of 2APl0 and the RC low pass filter formed.

HS3002 is selected in the amplification of described rectified signal, and it is high speed current feedback operational amplifier, is had up to 6500V/ μ s switching rate, 420MHz 3dB bandwidth and good inband flatness, in 115MHz gain only decline 0.1dB, it is very suitable for big signal amplification.

Main pulse when described single-chip microcomputer C8051F340 highests can provide 48 MHz counting, the counting time difference are 0.021 μ S, then wall thickness measuring error is 0.126mm, can reach high precision measurement requirement.

The interruption of described system using water steel boundary wave and steel bottom ripple as single-chip microcomputer C8051F340 after shaping is touched Signalling INT0 and INTl, when INTO interrupt produce when start timer count, when INTl interrupt produce when Off Timer simultaneously Timer count value is read, time counting value wall thickness value can be converted to by calculating.

The beneficial effects of the invention are as follows.

Imitate and tear system in the integrated gate control that ARM develops remote auto control with flow measurement measures, have it is stable, Flow measurement precision is high, simple to operate, to the strong adaptability of regimen, low cost and other advantages, can not only realize the accurate water distribution in irrigated area, section Scheduling and information system management are learned, and the working strength of watermaster can be mitigated, reduce water distribution dispute, information-based irrigated area is built not Have important practical significance.

Brief description of the drawings

The present invention is further described with reference to the accompanying drawings and examples.

Fig. 1 is systematic schematic diagram block diagram.

Fig. 2 is ultrasonic wave transmitting circuit.

Fig. 3 is low noise pre-amplification circuit.

Fig. 4 is variable-gain amplification circuit.

Fig. 5 is detection adjustable amplifying circuit.

Fig. 6 is gate circuit and shaping circuit.

Fig. 7 is time difference extraction timing diagram.

In Fig. 7,1- beginning ripples, 2- water steel boundary waves, 3- steel bottom ripple.

Embodiment

As shown in Figure 1.

In order to which real-time online detects thickness of workpiece, detection means is that 3 probes are on measured workpiece using triple channel 120 ° of placements.R and r is respectively the exradius and inner circle radius of workpiece.3 ultrasonic thickness measuring probes are arranged in A, B, C point, if 3 Point institute thickness measuring angle value is respectively ha, hb, hc, P1 (x1, y1), P：(x2, y2), P3 (x3, y3) are respectively A, B, C point sound wave incident Line and the deep hole hole wall intersection point to process, point O1 are the center of circle of deep hole, are also intended to determine the point of its coordinate position.According to probe position To put and understand 1=30 ° of θ, 3=270 ° of 2=150 ° of θ, θ and the thickness value measured can obtain 3 points on finished work hole wall of value, due to They are 3 points on a circle, therefore can obtain its center of circle O1 coordinate value (x, y), and are closed using rectangular co-ordinate and polar coordinates It is formula x=ρ cos θ and y=ρ sin θs, it is known that the center of circle O1 for the deep hole processed and the relative deviation in the benchmark center of circle 0, monitor work in real time The offset of part ensures the qualification rate of workpiece.

As shown in Fig. 2 the radiating circuit of ultrasonic wave is under transmitting burst pulse control, the height of excitation ultrasonic probe is produced Control signal is pressed, it is achieved thereby that ultrasonic wave is launched.In actual ultrasonic thickness measurement, generally by the high voltage burst pulse of several hectovolts Signal is added on ultrasonic probe, encourages the piezoelectric chip of ultrasonic probe to vibrate, and it is launched ultrasonic wave.In system using 600 V high-pressure modular, IRF840 are a N-channel enhanced power FETs, resistance to 600V high pressure, and conducting resistance is small. Entirely the operation principle of ultrasound emission circuit is：In no transmitting burst pulse, 600 V high pressures are filled by RGl, RG2 to CGI Electricity, the voltage difference at its both ends is set to reach+600 V or so.After launching pulse arrival, IRF840 conductings, now CGl passes through IRF840 Electric discharge, in the moment of its conducting, IRF840 drain voltage is smaller, drags down CGl current potential.Due to the voltage at electric capacity both ends It can not be mutated so that output end FSTl current potential is about one 600 V in moment, and this negative pulse acts on ultrasonic probe, makes it Piezoelectric transduction is produced, launches ultrasonic wave.RG5 is damping resistance in figure, and it is both that discharge time and hair are adjusted in discharge circuit Pulse strength is penetrated, also adjusts the width of ultrasonic pulse.The resistance is in parallel with ultrasonic probe, changes RG5 and also changes probe simultaneously Electrical damping size, that is, influence the resolving power of detection.In practical application, resistance can be set according to the different frequency of transmitting probe Put.

As shown in figure 3, in ultrasonic thickness measurement system, the quality of the echo-signal that sensor receives depends primarily on tested The surface configuration of object, the density of transmitting medium and distance etc..In addition, echo-signal would generally be done by a large amount of signals Disturb, including interference for introducing in itself of the disturbing of extraneous intrinsic target, the cycle of mobile target and random disturbances, analog circuit etc.. Therefore, receiving circuit must have stronger adaptability and the rejection ability to interference signal.Ultrasonic wave receiving circuit in invention It is made up of low noise pre-amplification circuit, VCA810 variable-gain amplification circuits, detecting circuit and gate control circuit.Low noise is put Big device (Low Noise Amplifier, LNA) is in front position in ultrasonic thickness measurement reception system, its performance indications it is good It is bad to have a significant impact to receiving circuit integrity.The mainly first order of reception system noiseproof feature is influenceed, so in system During design, preamplifying circuit should select the small amplifier of noise coefficient as far as possible and improve its gain as wide as possible.To reduce The noise of system, system select low-noise operational amplifier chip OPA2686, and the voltage noise of the chip is 1.4 nV/ (Hz) ^1/2, increase Beneficial bandwidth product is 1.6GHz.Wherein DAl, DA2 are that two backward diodeds shield, and prevent receiving circuit from overloading.Pass through The multiplication factor of its first order is adjusted to variable resistance WAl, suitably to amplify to the echo-signal of reception.The second level is One fixes amplifying circuit, while to prevent echo-signal from direct current biasing occur, makes echo-signal all the time in baseline by adjusting wA2 On axle.

As shown in figure 4, variable-gain amplification circuit continuously may be used using high-gain, low noise, low distortion, control range The voltage-controlled amplifier VCA810 of tune is completed.Powered using ± 5V, there is Differential Input Single-end output, stable gain band Width, low output DC error.Its operation principle is to realize gain control by the change to control voltage %, and control voltage is with increasing The relation of benefit is G=- 40 (K+1) dB.It will thus be seen that when control voltage K changes to -2V from 0 V, gain is linear from -40dB Ground changes to+40dB.System uses dc-couple mode, to prevent direct current biasing, using variable resistance WBl regulation Make echo-signal that it receives all the time on baseline.

As shown in figure 5, detecting circuit is made up of 2APl0 and the RC low pass filter formed.2APl0 has junction capacity It is low, the features such as working frequency is high and reverse current is small, to realize the envelope detection of signal.By the size for changing RCl0 and CC3 To change its upper cut-off frequency.In experiments it is found that when measurement thickness is smaller, bottom ripple Signal averaging can be made in initial spike It is interior, now it can reduce the conditions of streaking of initial spike by adjusting CC3 size, so as to realize the detection of high quality to improve thickness Spend the time sense of change.Compared with Voltage Feedback operational amplifier, THS3002 is high speed current feedback operational amplifier, With up to 6500V/ μ s switching rate, 420MHz 3dB bandwidth and good inband flatness, increase in 115MHz Benefit only declines 0.1dB, is very suitable for big signal amplification.The amplification of rectified signal is realized from the chip in invention, and it is dynamic State output area is up to 0-10V.

As shown in fig. 6, remove interference signal using gate control circuit, so as to retain useful signal, and by its useful signal Shaping circuit is given, accurately to obtain the time difference of water steel boundary wave and steel bottom ripple signal.

As shown in fig. 7, the signal after detection amplification first passes through voltage follower and keeps apart rectified signal and gate circuit, with Ensure the impedance matching of its circuit.By the signal of detection output, coupled capacitor CJl, CKl is formed into by triode output simultaneously Follower, it has the characteristics of big output impedance of input impedance is small, can reduce the internal resistance of prime amplifier, and improves amplifier Carrying load ability.Q1, Q3 emitter-base bandgap grading output end are believed detection by Q2, Q4 and signal strobe MK01, MK02 to realize respectively Number extraction at times.By signal JB01, JB02 with thickness information by LM393 anode compared with reference voltage, it is real The shaping of existing rectified signal so that it is unrelated relevant in the time to one with signal amplitude, in order to single-chip microcomputer come calculate by Survey the thickness of workpiece.

Using the water steel boundary wave after shaping and steel bottom ripple as single-chip microcomputer C8051F340 interrupt trigger signal INT0 And INTl, start timer count when INTO, which is interrupted, to be produced, Off Timer and read timer when INTl is interrupted and produced Count value, time counting value wall thickness value can be converted to by calculating.Single-chip microcomputer C8051F340 highests can provide 48 MHz meter Main pulse during number, the counting time difference is 0.021 μ s, then wall thickness measuring error is 0.126mm, can reach high precision measurement requirement.

Claims

1. a kind of inner eccentric holes detecting system is made up of two big modules, i.e. ultrasound emission receiving circuit part and single chip part； Ultrasonic wave transceiver circuit part receives amplifying circuit, adjustable gain amplification demodulatoring circuit, door by system power supply module, transmitting Circuit etc. forms；System uses pulse reflection thickness measuring method, and probe is using water immersion focusing compressional wave normal probe detection wall thickness；Transmitting electricity Road one rise time of output is very short, the very narrow periodicity electric pulse of pulse, is added to by cable on probe, encourages piezoelectric chip Produce ultrasonic pulse；After the ultrasonic pulse sent of popping one's head in enters workpiece, multiple reflections are formed on two surfaces up and down of workpiece；Instead Ejected wave is through piezoelectric chip reconvert into electric signal；After received circuit amplification, sound wave is measured in workpiece by time difference extraction circuit Propagation time t between two surfaces, so as to obtain the thickness of workpiece.

A kind of 2. inner eccentric holes detecting system according to claim 1, it is characterized in that the radiating circuit of described ultrasonic wave It is the high voltage control signal that excitation ultrasonic probe is produced under transmitting burst pulse control, it is achieved thereby that ultrasonic wave is launched.

A kind of 3. inner eccentric holes detecting system according to claim 1, it is characterized in that using 600 in described system V high-pressure modular, IRF840 are a N-channel enhanced power FETs, resistance to 600V high pressure, and conducting resistance is small.

4. a kind of inner eccentric holes detecting system according to claim 1, it is characterized in that described ultrasonic wave receiving circuit by Low noise pre-amplification circuit, VCA810 variable-gain amplification circuits, detecting circuit and gate control circuit composition.

A kind of 5. inner eccentric holes detecting system according to claim 1, it is characterized in that described variable-gain amplification circuit It is to be completed using the voltage-controlled amplifier VCA810 of high-gain, low noise, low distortion, control range continuously adjustabe.

A kind of 6. inner eccentric holes detecting system according to claim 1, it is characterized in that described detecting circuit is by 2APl0 Formed with the low pass filter of RC compositions.

7. inner eccentric holes detecting system according to claim 1, it is characterized in that the amplification of described rectified signal is selected HS3002, it is high speed current feedback operational amplifier, has up to 6500V/ μ s switching rate, a 420MHz 3dB's Bandwidth and good inband flatness, in 115MHz gain only decline 0.1dB, be very suitable for the amplification of big signal.

A kind of 8. inner eccentric holes detecting system according to claim 1, it is characterized in that described single-chip microcomputer C8051F340 is most Main pulse when height can provide 48 MHz counting, the counting time difference are 0.021 μ s, then wall thickness measuring error is 0.126mm, be can reach High precision measurement requirement.

9. a kind of inner eccentric holes detecting system according to claim 1, it is characterized in that described system is by the water after shaping Steel boundary wave and steel bottom ripple respectively as single-chip microcomputer C8051F340 interrupt trigger signal INT0 and INTl, when stopping pregnancy in INTO Start timer count when raw, Off Timer and read timer count value when INTl is interrupted and produced, can will by calculating Time counting value is converted to wall thickness value.