SU1346710A1 - Apparatus for detecting metal particles in moving fibrous material - Google Patents

Abstract

This invention relates to the detection of metallic particles in a moving fibrous material. The purpose of the invention is to increase the reliability of detection of metal particles. The metal particle 14 present in the controlled fibrous material 15, the passage in the zone of action of the metal particle sensor, including the high-frequency generator i, decreases the amplitude of its output signal while reducing the output signal of the detector 4. When the signal reaches a predetermined threshold, the pulse shaper 5 operates actuator 6. The self-tuning circuit of the amplitude of the high-frequency generator I includes a delay element, the value of which is determined by the sensor 10 the velocity of the control is from the fiber material being injected, and the integrator associated with the voltage setting device 11. 1 il. sl co 4 O5

Description

eleven

This invention relates to the detection of metallic particles in a fibrous material.

The purpose of the invention is to increase the reliability of detection of metal particles.

The drawing shows a block diagram of the proposed device.

The device contains series-connected sensor of metal particles, including a high-frequency generator 1, the oscillating circuit of which consists of coil 2 inductance and capacitance 3, detector Ai shaper 5 pulses, as well as an actuator 6. The self-tuning circuit includes series-connected voltage converter 7, a delay element 8 and an integrator 9, the sensor 10 of the speed of movement of the fibrous material is connected to the control input of the block 8 of the delay 8, and the setpoint generator 11 is connected to the integrator 9 no. The input of the auto-tuning circuit with the detector is 4, and the output is with a high-frequency generator 1. The power-exclusion circuit of the device when it is turned on consists of time relay 12 and logic element 13. Time relay 12 is connected to the first input of logic element I 13, the output of which is connected with the actuator 6, and a second pulse generator 5 is connected to the second input of the element I 13. Position in the diagram

14 denotes a metallic particle present in the controlled material 15.

The device works as follows.

The controlled fibrous material 15 moves relative to the metal particle sensor. If in controlled fibrous material

15 there is a metal particle 14, then during its passage in the working area of the electromagnetic field of the inductor 2, the amplitude of oscillations of the high-frequency generator I decreases, and consequently, the constant component of the voltage at the output of the detector 4 decreases, when it reaches a certain threshold value the output of the driver 5 pulses, a signal is generated, which includes the actuator

6. The duration of the pulse produced by the driver 3 is set from

102

Conditions for reliable actuation of the actuator 6.

At the same time, the signal from the detector 4 is fed to the input of the voltage converter 7, which performs the function of suppressing the variable component and amplifying the signal, and then through the delay element 8 the constant component of the signal goes to the integrator 9, which acts on the high-frequency generator I, increasing its voltage to the initial voltage determined by the voltage generator 11. The rate of change of the output voltage of the integrator 9 depends on its constant time, which is selected from the conditions for the stability of the auto-tuning system of the metal particle sensor with the required quality of stabilizing the output voltage amplitude of the high-frequency generator 1 against the background noise.

Due to the delay of the auto-tuning signal by the delay element 8, the information pulse from the high-frequency oscillator 1 does not change during the detection of the metal particle 14. metal particle 14 depends on the speed of its movement relative to the sensor of metal particles, therefore for In order to control the auto-tuning, a sensor 10 of the speed of movement of the monitored material is connected to the delay unit, the signal level from the output of which determines the duration of the negative feedback signal delay of the delay element 8.

During switching on the device transients occur in its blocks. In order to prevent actuator 6 from activating in this mode, time 12 serves as a trigger for generating a logical zero signal for the time after which the transition in the device blocks ends. The signal of the relay 12 time is fed to the input of the logical element And 13, to the other input of which receives a signal from the driver 5 pulses. As a result of the logical multiplication of these signals by

the output of the logic element 13 and there is a signal prohibiting the operation of the actuator 6 for the duration of the switching on transients.

Claims (1)

Invention Formula A device for detecting metal particles in a moving fibrous material, comprising a metal particle sensor, a detector, an output with a voltage converter, and an input with a metal particle sensor, an integrator and a voltage sensor, and the executer G. Volkova Compiled by B. Bykhovsky Tehred L. Serdyukova Proofreader V. But ha Order 5100/28 Circulation 419Subscription VNIIga of the USSR State Committee for inventions and discoveries N3035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 A tel mechanism associated with the detector output is characterized in that, in order to increase the reliability of detecting metal particles, it has a sensor for moving the fibrous material and an element backing, the converter output being connected through a series-connected delay element and an integrator with the control input of the metal particle sensor, and the control inputs of the delay element and the integrator, respectively, are connected to the sensor of the speed of movement of the fibrous material and the master voltage.