SU1302180A1 - Device for electromagnetic checking of moving ferromagnetic parts - Google Patents

Description

one

The invention relates to a measurement technique and can be used to conduct non-destructive testing of materials and products.

The purpose of the invention is to improve the noise immunity of the device.

FIG. 1 is a block diagram of the deviceJ in FIG. 2 - time diagram of his work.

The device contains a magnetizing system 1, a reading coil 2, the output of which is connected to the input of the amplifier 3, the output connected to the inputs of the key 4 and the first comparator 5, the output of the key 4 connected to the input of the integrator 6, and the output of the comparator 5 to the input of the imager 7 of the strobe impulse and direct ushm key input 4. The input element 8 delay 1302180 2

torus 5, the latter opens the key 4. In this case, the signal from the output of the amplifier 3 is fed to the input of the integrator 6 (Fig, 26). The signal at the last output is changed according to the law U,

 r-iО

 K U.dt, where K is a constant constant -1

Tegrator 6. In the initial state, the voltage at the output of the integrator 6 is less than the voltage specified by the source 13 of the reference voltage.

to

At time t, j (Fig. 2 g), when

the voltage on the integrator 6 exceeds the level of the reference voltage, the comparator 14 operates (Fig. 23), unlocks the element 15 and blocks the element 17 through the inverter 16. At the time t when the signal at the output of the amplifier 3 becomes less than the response threshold comparator 5, this

ki is connected to the start-up input of the analog-20 comparator operates again and closes the key 4. The voltage on the integrator 6 is proportional to the magnitude of the residual magnetic flux in the central section of the part 11. When the comparator 5 is repeatedly triggered at the output t shaper 7 appears pulse, which through the element And 15 (Fig.2e (d enters the gate input digital converter 9, the output connected to the input of the registration unit 10, and controlled part 11 is located on the conveyor 12 or d Vides along the guide groove (not shown). The output of the source 13 of the reference voltage is connected to the second input of the second comparator 14, and the output of the integrator is 6 25

with the first input of the comparator 14 and the input of the converter 9 and the input of the elec- tronic-digital converter 9, the output of the comparator 14 is connected to the first input of the element 15 and the input of the inverter 16, the output connected to the first input of the second element 17, whose output is connected with the first input element OR 18, the second input connected to the output of the element 8 delay. The output of the strobe pulse former 7 is connected to the second inputs of the AND 15 and 17 elements, and the output of the OR 18 element to the control input of the integrator 6.

The device works as follows.

The controlled part 11 passes through the conveyor 12 through the magnetizing system 1, where it is magnetized until it reaches the end. Reading coil

ment 8 delay. Through the blocked by the inverter 16, the second element And 17 strobe pulse from the output of the imaging unit 7 does not pass. For this -3535 pulse, the converter 9 performs analog-to-digital processing of the signal of the integrator 6 and provides information to the input of block 10, Element 8 delays the pulse from the driver 7 to

 the time required for actuation of the converter 9, after which the pulse from the output of the delay element 8 through the element RSHI 18 (Fig. 2) goes to the control input of the integrator 6 and resets it to zero. In this case, the comparator 14 is set to the initial state, locks the element AND 15 and through the inverter 16 unlocks the element AND 17. The device 2 is located behind the magnetizing system and is ready to control the next mine 1 in the course of the movement of the part being monitored. Details 11, Passing through the 2 reading, the magnetized part leads, in it

The signal, which is transmitted through the amplifier 3 by the interference signal, which enters the input of the amplifier 3 from the reading coil 2 (FIG. 2a, time t), goes to the inputs of the key 4 and the comparator 55 is characterized, as a rule, by the amplifier 5. At the time moment t (FIG. 28), with a tudoy comparable or even superior to the amplitude of the information signal and significantly less time when the signal at the output of the amplifier 3. will exceed the threshold srabatshan KomparaV time t, j (Fig. 2 g), when

the voltage on the integrator 6 exceeds the level of the reference voltage, the comparator 14 operates (Fig. 23), unlocks the element 15 and blocks the element 17 through the inverter 16. At the time t when the signal at the output of the amplifier 3 becomes less than the response threshold comparator 5, this

0, the comparator triggers again and closes the key 4. The voltage on the integrator 6 is proportional to the magnitude of the residual magnetic flux in the central section of the part 11. When the comparator 5 is triggered again at time t (Fig. 2e), a pulse appears at the output of the former 7 which is through element 15 (fig 2e (d enters the gate input for starting the converter 9 and the input

ment 8 delay. Through the blocked by the inverter 16, the second element And 17 strobe pulse from the output of the imaging unit 7 does not pass. For this -3535 pulse, the converter 9 performs analog-to-digital processing of the signal of the integrator 6 and provides information to the input of block 10, Element 8 delays the pulse from the driver 7 to

 the time required for actuation of the converter 9, after which the pulse from the output of the delay element 8 through the element RSHI 18 (Fig. 2) goes to the control input of the integrator 6 and resets it to zero. In this case, the comparator 14 is reset, locks the element 15 and, through the inverter 16, unlocks the element 17. under production conditions, this type of fur is induced on the pickup coil 2 when switching on and off engines, machine tools, powerful lamps, etc. The interference signal, as well as the information signal, triggers the comparator 5 and through the public key 4 enters the input of the integrator 6. The voltage at the output of the source 13 is selected by the voltage source so that the integrated signal of the unipolar interference signal does not exceed this tension. Then the integration of the interference signal does not cause the comparator 14 to work, and the And 15 and 17 elements remain in their original states. At the moment of time tg, when the signal of the interfering impulse at the output of amplifier 3 becomes less than the threshold of the comparator 5, the latter locks key 4. In this case, the former 7 forms a gate-pulse, which through the unlocked AND 17 element and the OR element

18 enters the control input of the integrator 6 and resets it to zero. Strobe-pulse element from the imaging unit 7 does not pass through the element 15 and does not cause false triggering of the converter 9 and the registration unit 10. Thus, the noise immunity of the device does not depend on the level of operation of the comparator 5, but is determined by the voltage of the adjustable reference voltage source, which allows it to be rebuilt from any interference whose volt-second area of the unipolar pulse of which is less than the minimum possible volt-second area of one-field ry pulse information signal. In practice, this provides a complete detuning from interference. Since the response level of the first comparator does not affect the noise immunity of the proposed device, it can be chosen close to zero, which will almost completely eliminate the effect of the speed of movement of parts on the results of the control.

Claims (1)

DEVICE FOR ELECTROMAGNETIC CONTROL OF MOVING FERROMAGNETIC DETAILS, containing a magnetizing system, a reading coil, the output of which is connected to the input of the amplifier, the output of which is connected to the inputs of the key and the first comparator, the output of which is connected to the input of the driver of the gate-gate pulse an integrator input, the output of which is connected to the input of the second comparator, a registration unit and a delay element, characterized in that, in order to increase the noise immunity of the device, a reference voltage source, an analog-to-digital converter, two AND elements, an inverter and an OR element are introduced into it, while the output of the reference voltage source is connected to the second input of the second comparator, the output of which is connected to the first input of the first element And and the output of the inverter, the output of which is connected with the first input of the second AND element, the output of which is connected to the first input of the OR element, the output of which is connected to the control input of the integrator, the output of which is connected to the input of the analog-to-digital converter, and the output d the gate-pulse driver is connected to the second inputs of both AND elements, the output of the first AND element is connected to the start input of the analog-to-digital converter and the input of the delay element, the output of which is connected to the second input of the OR element, and the output of the analog-to-digital converter is connected to the input of the block registration. 1 “1302