SU1665296A1 - Article scanning device - Google Patents

Abstract

The invention relates to acoustic methods of non-destructive testing. The aim of the invention is to increase the stability of the scanning trajectory during manual longitudinal movement of the carriage, both due to the impossibility of exceeding the threshold value of the speed of the longitudinal movement of the monitoring sensor, and by adjusting the frequency of the transverse movements of the monitoring sensor, depending on the magnitude of its longitudinal movement speed. Moving the carriage 2 along the guides 1 is carried out manually. When the longitudinal speed of the carriage 2 exceeds the threshold value detected by the signal of the speed sensor 7, a signal amplified by the amplifier and turning on the electromagnetic clutch 10 appears at the output of the comparison circuit. The latter, in the on state, counteracts the longitudinal movement of the carriage 2. The signal of the sensor 7 also controls the frequency generated by a controlled signal generator. The signal from the generator is fed to the electroacoustic converter 3. Due to the mounting of the base of the converter 3 on the carriage 2, its oscillatory mechanical system 5 transmits back and forth transverse movement to the sensor 6 of the control unit. The path of movement of the sensor 6 over the surface of the test article 12 is a uniform sinusoid regardless of changes in the speed of the longitudinal movement of the carriage 2. 4 Il.

Description

The invention relates to acoustic methods of non-destructive testing and can be used in the implementation of control methods that require a sensor to scan a product, in particular for ultrasonic (US) inspection of products with a welded seam using an inclined transducer.

The aim of the invention is to increase the stability of the scanning path.

in case of manual longitudinal movement of the carriage due to the impossibility of exceeding the threshold value of the speed of the longitudinal movement of the monitoring sensor, and adjusting the frequency of the transverse movements of the monitoring sensor depending on the magnitude of the speed of its longitudinal movement.

Figure 1 shows a device for scanning a product inspection sensor;

figure 2 - the same structural scheme; Fig. 3 shows the signals at the outputs of individual units of the device: a) a longitudinal speed sensor for moving the carriage; 6} controlled oscillator; c) amplifier; in fig. 4 shows the scanning path of the product control sensor corresponding to the output signals of FIG. 3.

The device for scanning the product contains guides 1, a carriage 2 mounted on the guides 1 with the possibility of longitudinal movement, an electro-acoustic transducer 3 with a base 4 and an oscillating mechanical system 5 and a control sensor 6, the base 4 of the transducer 3 is fixed on the carriage 2. The transducer system 5 3 is rigidly connected to the sensor 6 control. The device also contains a serially connected sensor 7 for a longitudinal speed of movement of the carriage 2, a threshold circuit 8, an amplifier 9 and an electromagnetic clutch 10. The clutch 10 is intended for coupling the carriage 2 to the guides 1. In addition, the device contains a controlled generator 11, the output of which is connected to the converter 3, and the input with the output of the sensor 7. The converter 3 and the generator 7 perform the functions of driving the transverse displacement of the sensor 6 of the control. Position 12 in figure 1 indicated a controlled product. The clutch 10 includes a shaft 13 engaged in coupling with a pulley 14, A rigid connection of the sensor 6 to the system 5 of the converter 3 is carried out by means of a crosspiece 15. During the monitoring, the sensors b and 7 are connected to an ultrasonic flaw detector 16. In the event that a controlled product 12 is a pipe, guides 1 are mounted on section 17, which is attached to product 12.

A device for scanning the product control sensor works as follows.

On the product 12, for example, a pipe, is fixed along with 17 with guides 1. Manually carry out longitudinal movements of the carriage 2 along the guides 1. Sensor 7, for example, transformer, generates at its output a signal U proportional to the longitudinal speed of movement of the carriage 2 (Fig .Behind). From the output of sensor 7, the signal enters a threshold circuit 8, made, for example, using a voltage comparator and an inverter, where it is compared with the reference voltage I0. If U U0, then the output of circuit 8 is absent. If U S U0, then the signal from the output of the circuit 8 is fed to the amplifier 9 and from its output

(fig.Sv) on the electromagnetic clutch 10. In the absence of a signal at the input of the clutch 10, the shaft 13 is in the open state, and the pulley 14 rotates freely without rendering

in opposition to the movement of the carriage 2. If there is a signal Ug at the input of the coupling 10, it triggers, the kinematic chain of the shaft 13 closes, as a result of which the pulley 14 cannot rotate. Strength of training

between the pulley 14 and the catfish 17, it opposes the longitudinal movement of the carriage 2, and the longitudinal movement speed of the carriage 2 decreases. The signal from the output of the sensor 7 also comes

to the control input of the generator 11, made, for example, in the form of a sinusoidal oscillator with a field-effect transistor as a voltage-controlled resistor. The frequency of the sinusoidal signal Un at the output of the generator 11 is determined by the speed of the longitudinal movement of the carriage (Fig. 36). The signal Un is supplied to an electro-acoustic transducer 3, made, for example, in the form of an electrodynamic transducer. The oscillatory mechanical system 5 of the converter 3 moves relative to its base 4 and transmits this through the cross beam 15

reciprocating movement of the sensor b control, for example, an inclined ultrasonic transducer. The amplitude of the transverse displacement S reaches 20-25 mm. Since the frequency of the signal on

The output of the generator 11 is determined by the sensor 7, the trajectory of movement of the sensor 6 along the surface of the product 12 is a uniform sinusoid regardless of changes in the speed of the longitudinal movement of the carriage 2 (Fig. 4). During scanning, the sensor emits ultrasonic pulses of an oscillation in product 12 using ultrasonic flaw detector 16 and receives ultrasonic pulses reflected by the product,

5 According to the parameters of the reflected ultrasound pulses, the quality of the product 12 is determined. When the flaw detector 16 is executed with an integrator, a U signal is sent from the sensor 7 to its input. The output voltage is 11V

0 integrator of flaw detector 16 is defined as

55

lW (t) - r / Uex. (t) dt. l

where m is the integrator time constant; t is the integrator time variable:

Uex (t) - KV (t),

K - coefficient of proportionality of the sensor 7;

V (t) is the coefficient of longitudinal movement of the carriage 2;

dt is the time increment;

That is, lW (t) -Mv (t) dt.

The voltage UBbix (t) at the output of the integrator of the flaw detector 16 is proportional to the path traveled by the carriage during the measurement time (t). Having numbered UBbix (t) and adding it to a voltage corresponding to the initial coordinate v0, we obtain the voltage corresponding to the coordinate at carriage 2 at some time point t. This information is used to accurately determine the location of the defect in the article 12.

Claims (1)

Invention Formula A device for scanning an article, comprising guides mounted on them with the possibility of longitudinal the carriage connected to the carriage control sensor and the drive lateral movement of the control sensor, characterized in that, in order to increase stability of the scanning path during manual longitudinal movement of the carriage, it is equipped with a series-connected sensor of the longitudinal speed of movement of the carriage, a threshold circuit, an amplifier and an electromagnetic clutch designed for coupling the carriage to the guides; the transverse movement of the control sensor is designed as a controlled generator with an electroacoustic converter; the base of the electroacoustic converter is fixed on the carriage; the oscillating mechanical system of the electroacoustic converter is rigidly connected to the control sensor; generator is connected to the output of the sensor longitudinal speed of movement of the carriage, 2 IchYach / 0 12 1 FIG. 2 but B C about about Figz Phie4 t t