SU1126862A1 - Electromagnetic flaw detector for checking moving parts - Google Patents

Abstract

ELECTROMAGNETIC DEFECTOR FOR MONITORING MOVING PARTS, containing a measuring transducer, a measuring unit connected to it, two additional transducers installed on both sides of the measuring transducer along the movement path of the parts, and a shaper of measurement intervals and pauses, whose inputs are connected to the outputs of additional transducers of the transducers of the transducers of parts, and which are connected to the outputs of the additional transducers of the transducers of the transducers of the parts and the pauses, which inputs are connected to the outputs of the additional transducers of the transducers of the transducers of the parts and the pauses of the measuring intervals and pauses, the inputs of which are connected to the outputs of the additional transducers of the transducers of the transducers and part of the transducers of the additional transducers of the transducers of the transducers and part of the transducers of measurement transducers and pauses. that, in order to increase sensitivity and stability in operation, it is equipped with a sampling-storage unit, the control input of which connected to the output of the measurement interval generator and pauses, adjustable signal divider, connected to the output of the sampling unit and linear operational amplifier, the first input of which is connected to the output of the measuring unit and the signal input of the sampling-storage unit, and the second input to the midpoint of the adjustable divider signal. SU) 00 Od N9

Description

I The invention relates to indiscriminate means of control and can be used for automatic inspection of moving parts. An electromagnetic defect is known that contains a measuring transducer, a measuring unit with a tracking corrective system and a linear amplifier 1 3. In the known device Against the background of the absolute value of the signal from the monitored part, the disturbance of the signal from the defective area is small, since it is not produced, it is further amplified, besides, the operation of the device is affected by the change in the clearance gap by the measuring transducer and the monitored part, as well as by the allowable variation of the electrophysical parameters of suitable parts, for example, due to the heat treatment regimes of different batches of parts. The closest to the technical essence of the invention is an electromagnetic flaw detector for controlling moving parts, containing a measuring transducer, a measuring unit associated with it, two additional transducers installed on both sides of the measuring transducer along the trajectory of movement 5, and for forking of intervals measurements and pauses, the inputs of which are connected to: the inputs of auxiliary converters L2 However, the known device is characterized by insufficient sensitivity to minor defects and, apart from that, instability in automatic control, since there is no output tuning of the output signal from the pedic factors acting in the control process (on the size of the gap, on the allowable variation of the electrical parameters of suitable parts), the purpose of the invention is to increase the sensitivity and stability in work. This goal is achieved by the fact that an electromagnetic flaw detector for controlling moving parts, containing a measuring transducer j, an associated measuring unit 5, two additional transducers, installed on both sides of the measuring transducer in the direction of the movement path of the parts, and 2 ..2 shaper of measurement intervals and pauses, inputs which is connected to the outputs of additional converters, equipped with a sampling-storage unit, the control input of which is connected to the output of the interval generator Considerations and pauses, an adjustable signal divider connected to the output of the sampling-storage unit and a linear operational amplifier, the first input of which is connected to the output of the measuring unit and the signal input of the sampling-storage unit, and the second input to the average leak of the adjustable signal divider. In FIG. a structural diagram of an electromagnetic flaw detector is presented; FIG. 2 shows the nature of the signals at the output 1 of the device from the defective part without reinforcement; in FIG. 3, the character of the amplified and normalized signal at the output 2 of the device from the deflection part. Electromagnetic flaw detector for controlling moving parts contains detail pipe 1 in the form of a vertically installed tube and a measuring transducer 25 fixed on it, xoTopbrii is connected with measuring unit 3, made, for example, in the form of serially connected autogenerator 4, detector S and buffer stage 6 two additional converter 7 and 8, installed on both sides of the measuring converter 2 along the path of movement of parts 9, shaper 10 measurement intervals and pauses, whose inputs are connected to the outputs of the auxiliary converters 7 and 8, the sampling-storage unit 11, the control input of which is connected to the output of the imaging unit 10 measurement intervals and pauses, regulating 1; the second signal divider 12 connected to the output of the sampling-storage unit 11 and the linear operational amplifier 13, the first input of which is connected to the 1 INPUT of the measuring unit 3 and the signal input of the sample-storage unit 11, and the second input to the midpoint of the adjustable divider 12 sigchit. Electromagnetic defect; cog1 works as follows. As part 9 approaches the measuring transducer 2, the envelope of the high-frequency signal;, from the output, and the measuring unit. inK-.Tyiiaet to the inputs of the linear operational amplifier 13, the inverting first input being fed directly from the output of the measuring unit 3, and to the second input through the sampling-collecting unit 11 operating in the sampling mode (i.e. tracking the signal) And through an adjustable divider of 12 signals. When the part 9 enters the sensing (near) zone of the measuring transducer 2, the auxiliary transducer 7 and shaper 10 intervals are measured: - the research institute and pauses puts the block 11 into the storage mode, i.e. fixing the signal level. The fixed signal level (Fig.) Is the reference for the entire measurement interval and is fed to the non-inverting second input of the amplifier 13. When a defective part passes through the measuring transducer 2, a slight disturbance introduced by the defect (Udef of Fig.2) repeatedly (K times) is amplified (see Fig. 3), and at the output of amplifier 13 there appear significant signal deviations that cannot be easily detected by an analyzer, for example, a marker of defects (not shown in FIG. 1). The transformer -2 is triggered by an auxiliary converter 8, shaper 10 switches sampling-storage unit 11 into sampling (tracking) mode, the monitoring cycle ends and the flaw detector is ready for the next measurement. Figure 2 shows the position and nature of the envelopes of the high-frequency signal 14 and 15 at the output of the measuring unit 3 before amplification. The deviations (scatter) by the average signal level, io, are due to the influence of destabilizing factors (temperature drift, supply voltages, etc.), as well as a change in the gap between the moving part 9 and the transducer 2 or the variation of the electrical parameters of the part. in the group fit, caused, for example, by various modes of heat treatment. With the passage of a defective part area, a slight deviation of the signal / 4 is observed. The usual subsequent amplification of the signal, say by K times, although it increases the disturbance from the defect, but also increases by K times all positive factors (for example, destabilizing) factors affecting the signal from the part. Therefore, further analysis of the signal from the part (for example, analysis of the similarity of the waveform of the high-frequency envelope of the measuring transducer with the shape of the reference part) is not possible with automatic high-performance detection of defects during long-term work under production conditions. FIG. Figure 3 shows the nature of the signal at the output of the highly sensitive meter, where the average signal level is determined by the adjustable divider 12 signal. Fixing the reference voltage Ug for a given measurement cycle makes it possible to correct all adverse factors (destabilizing, influence of the gap, heat treatment modes) before the measurement and to produce multiple amplification of disturbances from defects (curve 16, Fig. 3) in this short-term measurement interval. The invention allows to provide high sensitivity to minor defects during long-term operation and stability of the instrument.

willows.1

l / ff / rrfpga / f t / j / ffpjffftat Fi 2

) t.t

l /

tlHfnepSa / t Fieu J

Claims (1)

ELECTROMAGNETIC DEFECTOSCOPE FOR THE CONTROL OF MOVING PARTS, containing a measuring transducer, a measuring block connected to it, two additional transducers installed on both sides of the measuring transducer along the component path, and a shaper of measurement intervals and pauses, the inputs of which are connected to the outputs of the additional transducers, that, in order to increase the sensitivity and stability in operation, it is equipped with a sampling-storage unit, the control input of which is connected It is suitable for the output of the shaper of measurement intervals and pauses, with an adjustable signal divider connected to the output of the storage sampling unit and a linear operational amplifier, the first input of which is connected to the output of the measuring unit and the signal input of the sampling-storage unit, and the second input is connected to the midpoint of the adjustable signal splitter. No. yo> ! 126862