SU896536A1 - Flaw detector for inspection of articles while moving - Google Patents

Description

(54) DEFECTOSCOPE TO CONTROL PRODUCTS IN THEIR PROCESS OF THEIR MOVEMENT

one

The invention relates to non-destructive testing and can be used for flaw detection of extensive electrically conductive products in the course of their movement.

A known flaw detector with a device for blocking the edges of the product, comprising a measuring transducer connected in series 5 and a measuring unit, an auxiliary transducer installed in front of the transducer, a control unit connected by its input with an output of an additional transducer, a prohibition unit connected by its first input to the output of the control unit and its the second input - with the measuring unit, and the actuator connected to the output of the inhibit unit 1.

A disadvantage of the known flaw detector is the lack of reliable control, which is associated with the presence of an uncontrolled zone at the edges of the product.

The closest to the invention in technical essence and the achieved result is a flaw detector for monitoring 20 products in the course of their movement, containing a series-connected measuring transducer, measuring

unit and comparator unit, installed in series along the path of movement of the product with gaps relative to the measuring transducer and each other, two auxiliary transducers, control unit and actuator 2. However, this flaw detector does not have the necessary reliability of control, since it does not allow monitoring the area at the edges products.

The purpose of the invention is to increase the reliability of the control.

The goal is achieved by the fact that the flaw detector is equipped with a speed measurement unit connected by its inputs to auxiliary converters and its output to the first input of the control unit, and a driver of exemplary signals connected by its input to the first output of the control unit and its output with the second input of the comparison unit, the third input of the latter is connected to the second output of the control unit, and the output of the comparison unit is connected to the executive mechanism.

The drawing shows a flow chart of a flaw detector for a variant with digital processing of control signals.

The flaw detector contains the first and second auxiliary converters 1 and 2, the measuring converter 3, the speed measuring unit 4, the inputs of which are connected to the auxiliary converters 1 and 2, the measuring unit 5, the output of which is connected to the measuring converter 3, the control unit 6, the input of which is connected with the output of the speed measurement unit 4, the comparison unit 7, the first input of which is connected to the output of the measuring unit 5, the second input of the comparison unit 7 is connected to the second output of the control unit 6, the former 8 tsovyh signal input coupled to the first output of the control unit 6, and an output connected to a third input of the comparing unit 7, and an actuator 9 connected to the output of comparator 7. The product is indicated by the position 10.

In the digital version of the processing of control signals, the speed measurement unit 4 is recommended to be made containing a driver 11, the inputs of which are connected to auxiliary converters 1 and 2, the first reference generator 12, the first matching circuit 13, the first input of which is connected to the first output of the driver 11, the second the input of the first matching circuit 13 is connected to the output of the first reference generator. 12, the counter 14, the counting input of which is connected to the output of the first matching circuit 13, and the reset terminal of the counter 14 is connected to the second output of the driver 11, the code converter 15, the input of which is connected to the output of the counter 14. The control unit 6 is recommended to perform containing the second reference generator 16, the first divider 17 with a variable division factor, the signal input of which is connected to the output of the second reference generator 16, and the control input of the first divider 17 with a variable division factor connected to the output of converter 15 code, distributor 18, shaper 19 number of exemplary signals, the first input of which is connected to the third output of shaper 11, and the second input of shaper 19 of the number of exemplary signals is connected to the output of the first divider 17 with a variable division factor, and the output of shaper 19 of the number of exemplary signals is connected to the input distributor 18. Comparison unit 7 is recommended to be run containing a reversible counter 20, the reset bus of which is connected to the first output of the distributor 18, the second coincidence circuit 21, the first input of which one with the output of the measuring unit 5, the second input of the coincidence circuit 21 is connected to the second input of the distributor 18, the decoder 22, the control inputs of which are connected to the outputs of the reversing counter 20, and the gated input of the decoder 22 is connected to the fourth output

distributor 18. A shaper of 8 exemplary signals is recommended to contain a third reference generator 23, an encoder 24, the input of which is connected to the third output of the distributor 18, a second divider 25 with variable division factor, the signal input of which is connected to the output of the third reference generator 23, and the control the input of the second divider 25 with a variable division factor

0 is connected to the output of the digitizer 24, the output of the second divider 25 with a variable division factor is connected to the subtractive input of the reversible counter 20.

The flaw detector works as follows.

In the initial state, the outputs of block 6

controls are locked. The monitored product 10 moves through auxiliary transducers I and 2 and the measuring transducer 3, the distance between which is known. In the velocity measurement unit 4, the time of the beginning of the test article 10 between the auxiliary transducers 1 and 2 is determined. From the known distance and the measured time, the velocity of the product is calculated. When the beginning of the test article 10 enters the second auxiliary transducer 2, a signal is generated at the output of the velocity measurement unit 4. When information about the speed of the monitored product 10 and the signal about the occurrence of the beginning of the monitored product 10 to the auxiliary converter 2, the control unit 6 receives signals from the measurement unit 4, which generates signals that come to the imaging unit 8 of the exemplary signals and to the comparison unit 7. The frequencies of these signals depend on the speed of movement of the test article 10. Comparison unit 7 also receives information from the output of the measuring unit. In the imaging unit 8 exemplary signals, with a frequency set by control unit 6, exemplary signals equivalent to the signals from the output of the measuring unit 5 are generated when passing through the measuring converter 3 of the valid part 10. The comparison unit 7 analyzes the signals coming from the output of the measuring unit 5 and the imaging unit 8 exemplary signals. If these signals are not identical, the comparison unit 7 generates a signal arriving at the input of the actuator 9. The flaw detector

Q can be implemented in both analog and digital versions.

The following is one of the possible digital implementation options.

The speed measurement unit 4 operates as follows. The signals from the outputs of the auxiliary converters 1 and 2 are fed to the input of the imaging unit 11. From the output of the imaging unit 11, the first input of the first matching circuit 13 receives a signal corresponding to the beginning of the test item 10 passing through the auxiliary converters 1 and 2. The reference oscillator receives calibrated pulses. Depending on the speed of movement of the product 10, a different number of reference impulses are fed to the input of the counter 14. The number of pulses in the counter 14 is inversely proportional to the measured speed. The counter 14 is reset by the signal taken from the second output of the former 11 after the controlled device 10 passes the measuring converter 3. To coordinate the operation of the control unit 6 with the speed of the product 10, the code converter 15 is used.

The control unit 6 operates as follows. Stable high-frequency signals from the output of the second reference generator 16 through the first engine 17 with a variable division factor arrive at the second input of the former 19 of the number of exemplary signals. The frequency of these signals depends on the speed of movement of the products 10, since the control input of the first divider 17 with a variable division factor is connected to the output of the code converter 15. The signal arriving at the first input of shaper 19 of the number of exemplary signals from the third output of shaper 11 allows the distributor 18. The moment of arrival of this signal is characterized by the fact that the beginning of the monitored item 10 is between the auxiliary transducer 2 and the measuring transducer 3. This is due to that in this device the comparison of the signals from the measuring unit 5 and the imaging unit 8 of the exemplary signals begins slightly before the moment when the beginning of the test item 10 begins to enter the measuring converter 3. The periodicity of the flaw detector operation is set by the distributor 18, which is controlled by the shaper 19 of the number of exemplary signals. The number of cycles depends on the length of the controlled product 10 and the size of the critical defect. In block 7 of the comparison, in a digital form, the information from the output of the measuring unit 5 is compared with the information from the output of the imager 8 exemplary signals.

Comparison unit 7 operates as follows. Comparison of signals from the output of the measuring unit 5 and signals from the output of the imager 8 exemplary signals occurs in the reversible counter 20. If the signal from the output of the measuring unit 5 differs from the signal of the imager 8 exemplary signals by an amount greater

permissible, then at the output of the decoder 22 a signal appears indicating a defect. When a synchronizing signal appears at the fourth output of the distributor 18, the output of the decider 22 appears to be a signal arriving at the input of the actuator 9, which cuts off the defective items.

Shaper 8 sample sig;: lov works as follows. C signals

the output of the third reference generator 23 is fed to the signal input of the second divider 25 with a variable division factor. The division factor of the second divider 25 with a variable division factor is changed in such a way that the signals from the output of the second divider 25 with a variable division factor correspond to the signal m from the output of the measuring unit 5 as it passes through the measuring transducer 3 of the suitable product 10.

Thus, the proposed flaw detector allows to increase the reliability of control of products in the course of their movement due to the exclusion of uncontrolled end zones.

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Claims (2)

1. USSR Author's Certificate No. 481828, cl. Q 01 N 27/86, 1975. 2. USSR author's certificate No. 678401, cl. G 01 N 27/86, 1978 (prototype). R