RU62708U1 - ULTRASONIC DEFECTOSCOPE - Google Patents

Abstract

In order to increase the reliability of control and expand the scope of the ultrasonic flaw detector by providing the ability to control products of complex shape and with a high level of structural interference, an ultrasonic flaw detector containing a power source, a signal processor in series, containing a threshold device, a probe pulse generator, an ultrasonic transducer, an amplifier, frequency filter, analog-to-digital converter, indicator, equipped, according to the claimed technical solution, servo driver of the threshold level, the input of which is connected to the output of the analog-to-digital Converter, and the output of the servo driver of the threshold level is connected to the input of the threshold device.

Description

The inventive utility model relates to a control and measuring technique in the field of research and analysis of materials using ultrasonic waves, can be used to control the echo-pulse method of complex shapes, including railway rails and rolling stock, and is designed to detect local defects continuity of the base metal, welded joints and individual sections of rails, including those laid in the path, as well as to determine the coordinates of occurrence of detected defects.

Known ultrasonic echo-pulse flaw detector containing a probe pulse generator, a transducer, an indicator-display unit with sweep, control, indication and time selection circuits, an amplifier providing amplification of amplitudes of echo signals of various levels to values sufficient for their indication and registration and containing device for automatic detection and signaling of defects with a constant detection threshold level (“Ultrasonic flaw detector UD2-12”; http://xrs.ru/uzk/ud2-12.htm - see Appendix 1).

The disadvantage of this flaw detector is the low reliability of detection of small defects due to the masking effect of structural heterogeneities of the controlled products (for example, the granular structure of the metal).

Also known is an ultrasonic flaw detector containing a power source, a signal processor connected in series with a threshold device, a probe pulse generator, an ultrasonic transducer, an amplifier, a frequency filter, an analog-to-digital converter, and an indicator - display. The signal processor contains a synchronizer, a control unit for the temporal amplifier sensitivity control circuit and a threshold device with an adjustable and constant level of signal detection within the sensing cycle (UD2-70 Ultrasonic Flaw Detector; www.luch.ru./product/ud2_70.html - see Appendix 2).

The disadvantage of this flaw detector is the relatively low reliability of detection of echo signals from defects in the process of monitoring products of complex shape due to the lack of a flexible control circuit for the detection threshold level.

The objective of the proposed technical solution is to increase the reliability of control and expand the scope of the flaw detector by providing the ability to control products of complex shape and with a high level of structural interference.

The problem is solved due to the fact that an ultrasonic flaw detector containing a power source, a signal processor in series, containing a threshold device, a probe pulse generator, an ultrasonic transducer, an amplifier, a frequency filter, an analog-to-digital converter and an indicator, is equipped, according to a new technical solution, with a threshold level shaper, the input of which is connected to the output of an analog-to-digital converter, and the output of the servo threshold shaper nya is connected to the input of the threshold device.

The presence of distinctive features in the claimed technical solution allows us to conclude that it meets the condition of patentability “novelty”.

The patentability condition "industrial applicability" is confirmed by the example of a specific implementation.

The essence of the technical solution is illustrated in figure 1 structural and functional diagram of an ultrasonic flaw detector.

An ultrasonic flaw detector contains a power source 1, a signal processor 2 connected in series, comprising a synchronizer assembly 3 and a threshold device 4, a probe pulse generator 5, an ultrasonic transducer 6, an amplifier 7, a frequency filter 8, an analog-to-digital transducer 9, and a threshold level follower 10 and display indicator 11.

The device operates as follows.

A power source 1 is used to power the ultrasonic flaw detector devices. The synchronizer assembly 3, which is part of the signal processor 2, starts the probe pulse generator 5, which excites the ultrasonic transducer 6. The ultrasonic transducer 6 excites ultrasonic wave pulses in the controlled product and receives reflected echo pulses. These reflected echo pulses are fed to the input of the amplifier 7, the amplification of which is set by the operator of the ultrasonic flaw detector in accordance with the type

the controlled part, the required control zone and the instructions of the technological documentation for ultrasonic testing.

The amplified echo signals are fed to the input of the frequency filter 8 and then to the analog-to-digital converter 9, the servo driver of the threshold level 10 and the threshold device 4 included in the signal processor 2, after which they are transmitted to the indicator 11 for display and registration.

The tracking driver of the threshold level 10 provides the synthesis of the envelope of the amplitudes of the noise signals, the values of which within the sensing cycle vary relatively slowly in accordance with the function of attenuation of ultrasound in the material of the controlled product. This envelope is supplied to the threshold device 4 in the form of a “cut-off from below” voltage. Such a cut-off frees the signal at the output of the threshold device 4 from the bulk of the "interfering" signals, grouped by a plurality of small reflectors distributed in the object - metal grain, small tears, etc., and manifested, for example, in the form of so-called "noisy" rails. The formation of the cut-off voltage provides for the separation of fast changes - the fronts of the echo signals that occur when defects are detected, from relatively slow changes in the amplitude of the envelope of the "interfering" signals.

The operation of the inventive ultrasonic flaw detector is based on the operating principle of an adaptive detector, when the detector adapts to slow changes in noise level using a receiver with a “floating” threshold “bottom cut-off.” Rapid level changes due to the appearance of signals from defects cause the threshold device to trigger before the synthesizer threshold voltage can compensate for the change in the threshold level in accordance with the change in signal level at the output of the analog-to-digital Converter.

Thus, the use of a threshold level follower allows you to use the maximum sensitivity of an ultrasonic flaw detector to detect defects, limited only by the properties of the material and geometry of the products being monitored, in particular, long distances — rails, axles of wheelsets, etc., which can significantly increase the reliability control and expand the scope of the flaw detector.

Claims (1)

An ultrasonic flaw detector containing a power source, a signal processor in series, comprising a threshold device, a probe pulse generator, an ultrasonic transducer, an amplifier, a frequency filter, an analog-to-digital transducer, an indicator, characterized in that it is equipped with a threshold level tracking transformer, the input of which is connected to the output of the analog-to-digital converter, and the output of the servo driver of the threshold level is connected to the input of the threshold device.