SU1423290A1 - Apparatus for monitoring the wear of cutting tool - Google Patents

Abstract

The invention relates to a machine tool industry, in particular, to active monitoring of the wear of cutting tools, and can be used on machine tools with numerical and adaptive control for continuous and discrete monitoring of the performance of the cutting tool. The purpose of the invention is to increase the productivity of control by achieving the possibility of automatically adjusting the device to the measuring position of the parameter for estimating tool wear. The device is equipped with an average value determination unit 16 and a divider G7, which allows automatically setting the width of a narrow amplitude range. Supplying the device with a peak detector 18, a waiting multivibrator 19, whose input is connected to generator 8, and a digital-to-analog converter allows you to select the maximum value of the corresponding parameter for estimating wear of the cutting tool from all values of the signals in narrow amplitude ranges. 3 il. with (L

Description

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The invention relates to machine tool construction, in particular, to the control of the bioca of cutting tools, and can be used on machines with numerical BiBiM and adaptive control for non-heating and discrete control (operability of the cutting tool).

The purpose of the invention is to increase the productivity of the control by achieving the possibility of automatic adjustment of the device to the measuring position of the parameter for estimating tool wear.

Figure 1 shows the block diagram of the proposed device for monitoring the wear of the cutting tool; Fig. 2 shows electric signals of acoustic emission at the output of the main amplifier as a function of voltage-time (where Uj is the width of a narrow amplitude range proportional to the average amplitude value U; Nj are numbers of pulses in this amplitude range). Llithud); on fig.Z - amplitude distribution of acoustic emission signals (and d, 44) and change eg - Keny and (g peak detector (dotted line).

A device for monitoring the wear of the cutting tool contains a series-connected AE signal converter 1, preliminary installation 2, a block of 3 band-pass filters, a main amplifier 4, a discriminator 5 ,. binary counter 6 pulses C: regulating; in the number of binary bits, differential discriminator | 7 with adjustable discrimination thresholds, generator 8 linearly varying voltage, adder 9, discriminator 10 of the lower level, discriminator 11 of the upper level and a subtraction circuit 12, a dual counter of pulses 13, a digital-to-analog converter 14, a recorder 15, a block 16 determine the average value of the signal, a voltage divider 17, a peak detector 18, a waiting multivibrator 19, and an indicator 20.

The device works as follows.

Converter 1, for example, piezoelectric, transforms mechanical acoustic emission pulses from the cutting zone into electrical signals that come in at the high-frequency input of the preamplifier.

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Amplifier 2, the signal from the preamplifier 2 amplifier is fed to the bandpass filter unit 3, allowing you to select the most informative bandwidth of signals from the influence of a particular factor of the cutting process in the frequency band from 1500 kHz tool. From the output of the band-pass filter unit 3, electrical signals are fed to the main amplifier 4, which amplifies the signals to a level sufficient for the operation of subsequent units of the device. Further, the amplified signal Ug (,,, (. 4 from the output of the main amplifier 4 enters the input of the discriminator 5, which passes all acoustic emission signals exceeding in amplitude the level of intrinsic noise of the measuring equipment. Then the acoustic emission signal in the form of pulses is fed to the input binary counter 6, which counts the total number of pulses (N). Simultaneously from the output of the main amplifier 4, the signal goes to the input of the differential discriminator 7 and to the combined first inputs of the discriminator 10 lower level and the upper level of the screener 1I, as well as the input of the average value determination unit 16. The reference voltage I. The threshold discriminator 10 of the lower level comes from the generator of the linearly varying voltage, and the reference voltage Ug (, ix.e discriminator 11 of the upper level comes from adder 9, which summarizes the voltage U (,, xg generator. 8 and voltage U |., proportional to the average value of the amplitudes. Determining the average value of U carries out, block 16 determining the average value and the coefficient of proportionality K (for example, O, 1) is set using the divider 17. voltage. Thus, the reference voltage of the upper level discriminator 11 is Usbix.g Ugfc, x.g + K-U. The pulses produced by the discriminator 10 of the lower level, from signal amplitudes exceeding the reference voltage U g, g / post-fall on the subtraction circuit 12. The pulses produced by the upper-level discriminator 11 from the amplitudes of the signal Ugbix.4 exceeding the reference voltage U g (Fig. 2) also arrive at this circuit. The subtraction circuit 12 ensures that at its output the number of pulses B is obtained in a narrow amplitude range. The generator 8 of linearly varying voltage allows this range to be moved from minimum to maximum amplitudes. From the output of circuit 12, the pulses are fed to the input of a binary counter 13, which counts the number of pulses NI in a narrow amplitude range over the entire amplitude spectrum. From the output to the binary counter 6 with an adjustable number of bits, the signal is fed to the reset input of the binary counter 13. The binary counter 13 is reset when the binary counter 6 overflows, which counts the total number of pulses, pulses ZN, therefore the output is proportional to an increase in the frequency of amNK slobs

The increasing voltage of the MIC and charging the memory over narrow ranges U amp.

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occurs up to the maximum value of the voltage Ujj. i4 mcc. Further, the voltage UBMV decreases. , and the peak IB detector remembers. the maximum value of Jettx.H MdKc that occurred during this measurement cycle of the tool wear parameter. The maximum value of the voltage UKMK.M is proportional (Nb).

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stored at the output of the peak detector 18 and on the indicator 20

On the other hand, a number is generated up to 20. Up to the moment of occurrence and waiting for the multiplier is proportional to the ratio of the number of the vibrator 19 short pulse pulses NcB to the narrow amplitude range of the peak detector 18. Next, the cue to the total number of pulses TY. CyF automatically repeats the described analogue converter 14 converts the data of the binary counter 13 into an analog value for further output of the results to the recorder 15 and to the input-PEAK detector 18. The recorder 15, which can be used as an oscillocycle from measurement (indication) of the parameter 25 evaluation of wear of the cutting tool.

Formula of Invention

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A device for monitoring the wear of a pew holding tool, comprising a transducer, a pre-amplifier, a bandpass filter unit, a main amplifier, a discriminator, connected to each other in series,

differential discriminator, disparity on screen for

j, t-g. f 35 low-level criminator, discriminator, registers the distribution of amplitudes over narrow bands L C MPAMUD

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NK f (g-) or displays additional visual controls. Determining the value of the parameter

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The linearly varying voltage generator 8 triggers a sweeping multivibrator 19, which ejects a short reset pulse of the peak detector 18 (at the end of the previous measurement cycle) to the output voltage Ug ,,, (g of the peak detector equal to zero. Then the generator 8 delivers the linearly increasing voltage g to the inputs of the discriminator 10 of the upper level and the discriminator 11 of the lower level, thereby the input of the peak detector 18 comes from the output of the digital-to-analog converter 14 a step-wisely increasing voltage U gj ,,, j. An increase in voltage. 14 occurs pro40

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the upper level, the first inputs of which are connected to the input of the main amplifier, the subtraction circuit, the first and second inputs of which are connected to the outputs of the discriminators of the lower and upper levels, respectively, the first binary counter, the second binary counter, the first input of which is connected to the output of the first binary counter, the hysterator A digital tax converter whose input is connected to the output of a second binary counter, characterized in that, in order to increase the productivity of the control, a generator, an adder, the output of which is connected to the second input of the discriminator, the upper level, the series-connected average value determination unit, the divider whose output is connected to the first input of the adder, the waiting multivibrator, the peak detector, the indicator, and the input of the waiting multi-up to the moment of occurrence and waiting for the multi-vibrator - a short pulse reset tivibrator 19 of a peak detector 18. Next, the described automatically repeats

measurement cycle (indication) of the cutting tool wear assessment parameter.

Formula of Invention

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the upper level, the first inputs of which are connected to the input of the main amplifier, the subtraction circuit, the first and second inputs of which are connected to the outputs of the discriminators of the lower and upper levels, respectively, the first binary counter, the second binary counter, the first input of which is connected to the output of the first binary counter, the hysterator A digital tax converter whose input is connected to the output of a second binary counter, characterized in that, in order to increase the productivity of the control, a generator, an adder, the output of which is connected to the second input of the discriminator, the upper level, the series-connected average value determination unit, the divider whose output is connected to the first input of the adder, the waiting multivibrator, the peak detector, the indicator, the input of the waiting multivibrator combined with the second input | Dam of the adder and discriminator of the lower level and connected to the generator output, the discriminator output connected (connected to the input of the first binary counter), the output of the subtraction circuit connected to the second input of the second binary switch etchika yield lduschego multi stomach.

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The vibrator is connected to the first input of the peak detector, the output of which is connected to the indicator, the output of the digital-to-analog converter is connected to the recorder and the second input of the peak detector, and the input of the average value determination unit is connected to the output of the main amplifier.

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Claims (1)

Claim A device for monitoring wear of a cutting tool *, comprising a converter, a preliminary amplifier, a block of bandpass filters, a main amplifier, a discriminator connected in series, a differential discriminator, a lower level discriminator, a upper level discriminator, the first inputs Determining the value of the LCP parameter Avw) - cutting wear rating on InetLN max 4L rument is automatically carried out as follows. The ramp voltage generator 8 traces a trailing edge 19 by the trailing edge, which generates a short reset pulse ^{45 of the} peak detector 18 (at the end of the previous measurement cycle) to the output voltage U _{Bb (x} . _{(G of the} peak detector equal to zero. Then the generator δυ * delivers a ramp voltage U _{eux g} discriminator 10 to the inputs of the upper level and the lower level discriminator 11, thereby at the input of the peak detector 18 is output from the DAC 14 increases abruptly tense e U _O. Increasing U _61H voltage. 14 comes about which is connected to the input of the main amplifier, the subtraction circuit, the first and the second input of which is connected to the outputs of discriminators lower and upper levels respectively, the first binary counter, the second binary counter, a first input of which is connected to the output of the first binary counter, a registrar, a digital-to-analog converter, the input of which is connected. to the output of the second binary counter, characterized in that, in order to increase the monitoring performance, a herator, an adder, the output of which is connected to the second input of the upper discriminator, a series-connected block for determining the average value, a divider, the output of which is connected to the first input of the adder, a multivibrator, a peak detector, an indicator, and the input of a standby multivibrator 5 is combined with the second inputs the adder and the discriminator of the lower level and is connected to the output of the generator, the output of the discriminator is connected to the input of the first binary counter, the output of the subtraction circuit is connected to the second input of the second binary counter, the output of the waiting multi-vibrator is connected to the first input of the peak detector. the output of which is connected to the indicator, the output of the digital-to-analog converter is connected to the recorder and the second input of the peak detector, and the input of the average value determination unit is connected to the output of the main amplifier. Compiled by A. Grishin Editor T. Parfenova Tehred L. Serdyukova Proofreader N.Korol Order 4472/15 Circulation 880 Subscription VNIIIPI of the USSR State Committee for Inventions and Discoveries 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and printing company, Uzhhorod, st. Project, 4