SU1442875A1 - Device for checking the blunting of cutting tool on numerically controlled machine tools - Google Patents

Description

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the initial cutting point is memorized in block 25 of the CHLU. On the Control signal, the cutter returns to the starting point of the cut, then the cutter moves in steps towards the part, the coincidence circuit 14 opens, the trigger 15 opens the coincidence circuit 15, the input of which receives the increment pulses of the cutter. Simultaneously, these pulses are used to start up the control unit 19 and measure the machine vibrations. Moe

The touch of the part by the cutter is fixed by the appearance of a signal at the output of the counter 17, while the trigger 10 locks the coincidence circuit 14, stops the movement of the cutter. At the output of the counter 18 and the display unit 23, information on the tool wear is displayed, the value of which is proportional to the code of the number of steps from the initial coordinate Xd, which is touched. 1 il.

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The invention relates to the measurement of tool wear and can be used in machines with a CNC system,

The purpose of the invention is to improve the accuracy of control of wear of the cutting tool

The drawing shows a diagram of the device control blunting cutting tools on CNC machines,

The device comprises a vibration sensor 1, an amplifier 2, a filter 3, a detector 4 with two inputs, a comparison circuit 5, a bias voltage source 6, a voltage divider 7, an integrator 8, triggers 9 - P, a coincidence circuit 12-15, an exemplary frequency generator 16, pulse counters 17 and 18, control block 19, code-voltage converter 20, decoder 21, register 22, digital readout block 23, NOT 24 circuit, the device interacts with the CNC block 25.

Vibration sensor 1, amplifier 2 and filter 3 are connected in series. The output of the filter 3 is connected to one of the inputs of the detector 4, the output of which is connected to one of the inputs of the comparison circuit 5, the second input of which is connected to the output of the bias voltage source 6 through serially connected voltage divider 7 and integrator 8. The output of the comparison circuit 5 with the installation input of the trigger 9j, the output of which is connected to one of the inputs of the circuit 12 coincides with two inputs, the second input of which is connected to the output of the generator 16 of the reference frequency.

The output of the coincidence circuit 12 is connected to the input of the pulse counter 17,

The outputs of the control unit 19 are connected to the controllers 1a, by the inputs of the voltage divider 7 and the integrator 8, to the fault inputs of the trigger 9 and the counter 17, and to the inputs of the decoder 21 and

multiple input matching circuit 13. Converter 20 code - voltage is connected between the source 6 of the bias voltage and the second input of the detector 4o Pulse counter 17 output

connected via the decoder 21 to the input of the trigger 10; at the same time, the output of the pulse counter 17 through the coincidence circuit 13 is connected to the input of the register 22, the output of which is connected to the control input of the converter 20 code - voltage. The inputs of the coincidence circuit 14 are connected to the code registers of the initial coordinates of the cutting process of the NC block 25, its output Control and

to the inverse output of the trigger 10, and its output is connected to the setup input of the trigger 11. The output of the latter is connected to one of the inputs of the coincidence circuit 15, the second input of which is connected to the output of the pulse generator to control the stepper motor in the CNC unit 25, and its output is connected to the input of the counter 18 pulses, the output of which is associated with block 23

digital readout. The direct output of the trigger 10 is associated with the CNC unit 25, the start input of the control unit 19

with the appropriate output blodinen

25 CNC, and the reset inputs of the triggers 10 and 11 are connected to the output of the control unit 25 CNC through the circuit NOT 24

The device works as follows

When the machine is turned on before the process, a combination of the nu- and the cutter is made and the cutting is measured - details

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vibroacoustic signal for idle machine vibration. In this case, the control unit 19 generates a strobe-pulse for resetting the integrator 8 and setting the trigger 9 to the initial state. The voltage of the vibro-acoustic signal of the machine idling from the vibration sensor 1 is fed through amplifier 2 and filter 3 to the input of detector A, which converts the alternating voltage to after) a), going to the input of the comparison circuit 5, the second input of which receives a sawtooth voltage from the integrator 8 according to the signal of the control unit 19, opening the voltage divider 7, to the input of which the voltage of the bias voltage source 6 is applied. At the same time, trigger 9 is cocked; and the generator pulses of the exemplary frequency pass through the open circuit 12 to match the input of the pulse counter 17 until the value of the sawtooth voltage is equal to the voltage from the output of the detector 4. At the moment of their equality, the comparison circuit 5 operates, which resets the trigger 9, the output signal which locks the match 12 match. The information in the pulse counter 17 records the value of the vibration when the machine is idling with SHU. The signal from the control unit 19 opens the coincidence circuit 13 and the information from the pulse counter 17 is copied to the register 22, which, by the converter 20, controls the code-voltage, inputs the compensating voltage into the detector. The voltage at the detector output becomes zero. The vibration of the vibroacoustic signal of the counter reading 17 is made to become zero. After that, the CNC machine switches to the working cutting mode. The coordinates of the first operating point in the manufacture of the part are memorized in block 25 and used later for control.

After the end of the technological cycle or after the specified operating time of the cutting tool

g in block 25, the program generates a control operation signal. By this signal, the npo-i cutting process stops and the tool returns to the first work point, After

0 hitting the tip of the cutter to the XoZo point starts the step-by-step working out of moving the cutter in the direction of the part if, as a result of the wear of the cutter, when the cutter touches the part at the point

5 no. The trigger 10 is in the zero state, and the coincidence circuit 14 is opened by the command Control. The signal from the output of the coincidence circuit 14 triggers trigger 11 and opens

0 scheme 15 matches. At each step of approaching the part to the workpiece from the output of block 25, a pulse arrives at the second input of circuit 15. The number of these pulses is counted by a counter 18 of the tool wear amount. At the same time, for each pulse from the output of block 25, the control block 19 is started and the vibration level of the machine is measured. Since the voltage at the input of the detector 4 is compensated, zero readings are recorded in the meter 17. At the moment when the cutter touches the part, some code appears in the counter 17. The difference between this code and the zero level is decrypted by the decoder 21, the output signal of which sets the trigger state to one. The output signal of this trigger blocks the circuit 14 preventing further passage of pulses to the counter input 18. At the same time, the output signal of the trigger 10 is fed to the input of block 25, stop moving the cutter to the part. As a result, in the counter 18, the code of the number of the pins from the initial coordinate XgZg until the moment of contact is stored, corresponding to the dimensional wear of the cutting tool in the steps of the CNC machine, the digital display unit 23 shows the tool wear.

Claims (1)

Invention Formula The control device for blunting a cutting tool on CNC machines contains a control unit; n, the trigger input of which is intended for  51442875 .6 With the output of the CNC, the sequence of the input of the first additional circuit but the connected vibration sensor, a prematch, the output of which is connected to the transmitter designated for measuring the vibrations at the register input, a converter. cutting tool amplifier Code 5 - the voltage of the code input is connected to the register output, the analog input to the output of the bias voltage source, and the output to the second input of the detector, the output of which filter and detector, serially connected integrator comparison circuit, trigger and coincidence circuit, exemplary frequency generator, pulse counter, decoder, bias voltage source, voltage divider and digital readout unit, exemplary frequency generator output connected to another coincidence circuit input, pulse counter the input is connected to the output of the coincidence circuit, and the output to the input of the decoder, the output of the bias voltage source is connected to the input of the voltage divider, and the output of the control unit is connected to the control For the integrator input and the trigger reset input, it is different from the fact that, in order to increase accuracy, it is equipped with three additional codes — the voltage of the code input is connected to the register output, the analog input to the output of the bias voltage source, and the output to the second th detector input, the output of which 10 is connected to another input of the comparison circuit, the output of the decoder is connected to the setup input of the first additional trigger, the forward output of which is intended to be connected 15 to the input of the CNC unit, and the inverse output is connected to the input of the second additional matching circuit, the second input of which is intended to be connected to the output Control block 20 CNC, the reset inputs of additional triggers are connected to the output of the NOT circuit, the input of which is intended to be connected to the Control output of the CNC unit, the third input is the second additional matching circuits, register-25 of a matching coincidence circuit predator, converter code - for example, to connect to exit code the same, two additional trigger-coordinates of the CNC unit, the second input, an additional pulse counter-additional trigger is connected ow and the NOT circuit, the control input, the reptile of the second additional circuit the voltage divider is connected to the second-to-30 coincidence, one input to the third additional output of the control unit, and its exponential matching circuit the connection to the signal input of the integrator, to the output of the second additional third output of the control unit of the sub-trigger, another input is intended keys to the second input of the decoder connecting to the output of the stepper and the input of the first additional circuit 35 pulses of the CNC unit, the output of the third match, the fourth output of the blockade matching circuit control is connected to the input and zero is connected to the input of an additional pulse counter, the outputs of which pulse counter, the output of which pogo connected respectively to connected to the digital readout unit. the second input of the decoder and 40 the code — the voltage of the code input is connected to the register output, the analog input to the output of the bias voltage source, and the output to the second input of the detector, the output of which connected to another input of the comparison circuit, the output of the decoder is connected to the setup input of the first additional trigger, the direct output of which is intended to be connected to the input of the CNC unit, and the inverse output is connected to the input of the second additional coincidence circuit, the second input of which is intended to be connected to the output of the Control unit CNC, the reset inputs of additional triggers are connected to the output of the circuit NOT, the input of which is intended to be connected to the output of the Control of the CNC, the third input is the second additional