SU1177135A1 - Apparatus for monitoring machine-tools - Google Patents

Abstract

A MACHINE CONTROL DEVICE containing a vibration transducer and connected in series a bandpass amplifier, a bandpass filter, a detector with a built-in low-pass filter, a comparator, a two-input element AND, a machine control unit, characterized in that, in order to expand its functionality, the United successively a second bandpass filter associated with the output of a bandpass amplifier, a second detector with an integrated low-pass filter, a second comparator, a NOT element, a second a two-input element AND whose output is connected to a machine control unit connected through an input setting unit of settings to a second input of a second comparator and an input delay element, the second input of a delay element connected to a control unit of a machine, output connected to a second input of a second element AND and the second input of the first element is AND is associated with the control unit of the machine. (L

Description

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The invention relates to the field of machine tool construction and can be used to control the machining process on machine tools.

The purpose of the invention is to expand the functionality due to the possibility of determining tool breakage, failure to supply the workpiece and exceeding the limit dynamic loads on the machine.

The drawing shows a functional diagram of the device for controlling machine tools.

The device contains a vibration converter 1 mounted on the spindle bearing of the machine, band amplifier 2, band-pass filters 3 and 4, detectors 5 and 6 with built-in low-pass filters, comparators 7 and 8, HE element 9, two-input elements I 10 and 11, block 12 setpoints and an adjustable delay element 13, the inputs of which are connected to the corresponding outputs of the machine control unit 14.

The principle of operation of the device is based on receiving a signal from the vibroacoustic emission sensor about the presence of a cutting process and at the same time a signal that the machine support is in the “Working feed” mode.

If the tool breaks down or the workpiece is not supplied to the machining area, there is no signal about the presence of the cutting process at those moments when it should be according to the program. In this case, the device switches on the signaling machine and stops the operation of the machine at the end of the elementary cycle.

The device protects the machine from extreme dynamic loads, turns off the feed and rotation of the spindle when a large amplitude oscillation occurs in the AIDS system.

The device works as follows.

The signal from the vibration converter 1, mounted on the spindle bearing, is fed through a band-pass amplifier 2 to the inputs of the band-pass filters 3 and 4. The band-pass filter 3 is tuned to the fundamental natural frequency of the machine spindle. The amplitude of oscillations at this frequency reflects the dynamic load on the spindle, which may exceed the permissible value at critical tool wear, incorrectly chosen operating modes and various emergency situations. The signal from the band pass filter 3 is detected and smoothed by a detector 5 with an integrated low pass filter and fed to a comparator 7.

When the voltage at the output of the detector 5 of the response voltage of the comparator 7 is exceeded (the response voltage of the comparator 7 is set in advance during the device tuning), the comparator 7 is activated and the logical "1" appears at its output and goes to the element 10. the second input element And 10 from the CNC system of the machine is fed a logical unit in the case when the spindle is rotating. Thus, if during the rotation of the spindle ("1 at the second input of the element And 10), the dynamic load in the machine tool AIDS system is exceeded, which is recorded by the converter 1 and results in the operation of the comparator 7

 ("1 at the first input of an AND 10 element) at the output of an element of And 10 a logical" 1 appears, which is fed to the CNC system and stops the machining process. Element And 10 prevents false triggering of the device during auxiliary operations on the wall.

The second channel, consisting of a band-pass filter 4, a detector b with an integrated low-pass filter and a comparator 8, is used to receive a signal about the presence of a process

0 cut. The band-pass filter 4 is tuned to a frequency in the range of 10-30 kHz, at which the ratio of the signal from the cutting process to the noise of the rotating bearing is maximum.

5 To increase the sensitivity of the device, the comparator 8 is made with an adjustable threshold, the change of which is set from the setting unit 12, for each instrument separately. The need for this is due to the fact that the noise level of the spindle bearing depends significantly on the speed of its rotation.

Next, the signal about the presence of the cutting process from the output of the comparator 8 is fed through element 9 NOT to the input of element AND 11. To the second input of element AND, through the adjustable delay element 13, a signal is sent from the machine control unit 14 to activate the working feed.

Consider the operation of this part of the circuit for the case when the cutting tool is broken. At the output of the comparator 8 there will be a logical ' 1, since the signal from the cutting zone formed by the chains 1, 2, 4, 6 and 8 will be absent (the cutting tool does not touch the part, as it is broken). This "O is inverted by the element NOT 9 and the input of the element And 11 comes" The second input of the element 11 after switching on the working feed and the time set by the delay element 13 also receives the signal "1. Receipt of two

0 logical «1 to the inputs of the element And 11 will result in the appearance of the signal« 1 at its output, which enters the CNC system, stop the machine and turn on the call signal of the adjuster.

5 Thus, the signal at the output of the element 11 will be only if there is no signal about the presence of the cutting process from the output of the comparator 8 to

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after a predetermined time after the device has been turned on at the moment of switching on the working part of the working feed. A signal from the feed output when the tool is only supplied to the circuit AND 11 is fed to the control unit 14 to the part. Moreover, the delay time T on the machine, enables you to change the call separately for each innaladchik at the end of the elementary cycle using the job setting unit 12 and Stops the machine that is associated with the unit 14 controllable delay element 13 introduced what tool is this

den to prevent false triggers — time is in operation. lazy machine and receives information from her

Claims (1)

DEVICE FOR CONTROL OF MACHINES, comprising a vibration transducer and a series-bandpass amplifier, a bandpass filter, a detector with an integrated low-pass filter, a comparator, a two-input element And, a machine control unit, characterized in that, in order to expand the functionality, it is additionally connected sequentially a second bandpass filter associated with the output of the bandpass amplifier, a second detector with an integrated low-pass filter, a second comparator, an element NOT, a second two-in one AND element, the output of which is connected to the machine control unit connected via the entered set-point setting unit to the second input of the second comparator and to the input delay element, the second input of the delay element being connected to the machine control unit, the output is connected to the second input of the second And element, and the second input of the first AND element is connected to the machine control unit. ®