DE3643515A1 - Method of nondestructively testing metal pipes and rods and device for carrying out the method - Google Patents

Abstract

In the nondestructive testing of metal pipes and rods, for example using ultrasonic test devices, the end faces of the specimens are sources of pseudo errors, with the result that the test data obtained in the course of the test operation in the end sections of a specimen are unusable. Hitherto, untested sections of specified length were therefore provided at the beginning and end of a pipe. When the pipes or rods were used, the untested end sections were ignored or a specified length greater than the untested end sections was sawn off. According to the invention, the nondestructive test systems, in this case an ultrasonic test line, are provided with a pipe-end marking device which is controlled by the test system and which marks the untested sections at the end and beginning of each pipe with a fluorescent paint so that the untested sections are clearly recognisable. As a result, there is the possibility of providing the smallest possible untested end sections for various pipe and rod types. The fluorescent paint can be detected by a suitable detector so that the untested ends can automatically be sawn off. <IMAGE>

Description

The invention relates to a method for destruction free testing of pipes and rods made of metal, as well a device for performing the method.

Pipes and rods made of metal are usually used in Continuous process tested non-destructively, e.g. B. with Using an ultrasonic probe in a test station, through which the test object with defined speed runs through. There are also test facilities that based on magnetic induction or leakage flux. The following is intended specifically for testing pipes made of steel and non-ferrous metals. It understands but that the explanations also for massive Poles apply.

With the usual non-destructive testing methods, who for example cracks or inclusions in the measure material determined. The face of the item to be checked Rohrs are a source of error, since the in these Areas obtained test data not clearly say whether any error data determined by a Material defects or caused by the pipe end will.

So far you have at the beginning and end of the pipe a section of predetermined length is provided in to whom the evaluation of the test data has been blocked. These lengths were then later before Sawing off further processing of the pipes. At under Different pipe lengths and pipe types were used for the Pipe start and pipe end a single length cut or only very few lengths  see to make sure that only the past agreed length section was sawn off. According to experience but are the pipe end sections, where possible erroneous test data arise, with difference pipe types of different lengths. You face it on a single length section, which also the worst case, so certain Pipe types cut unnecessarily long end sections. Optimization in the sense that from abge each tube as small as possible end section will cut.

Accordingly, the invention is based on the object Process for non - destructive testing of pipes and Bars of metal according to the preamble of claim 1 to create, in which the untested and therefore un usable pipe ends can be varied in length can, but there is still the possibility, exactly to the unchecked end sections of the pipe know and saw off.

This object is achieved by the specified in claim 1 Invention solved. Through the automatic marking of the unchecked sections at the beginning of the pipe and at the pipe The end is in the later processing of the pipes time to see where the unchecked sections are start. Therefore, there is the possibility, for example Different lengths for different pipe types to provide checked end sections.

The marking preferably consists of a color coating wear, for example made of fluorescent paint. The fluorescent color allows automatic Er know the pipe sections to be sawed off with the help of a  suitable detector device. The are preferred end sections to be cut later at the beginning of the pipe and at the pipe end (in the transport direction during the test process seen) with a paint application, but it is also basically possible, the paint application exactly in the mean lying between the mentioned sections section. This marking of the test object takes place after the DUT through the test station has run.

The invention also provides an apparatus for Carrying out the method according to the invention. A such a device is specified in claim 4. Next Formations of the device are in claims 5 and 6 specified.

In the device according to the invention, pipe start and pipe end from a detector, e.g. B. a light barrier arrangement detected. The further course units located on the transport track, namely the Test station with test head and the paint spraying station with paint spray head, have this detector direction a defined distance. With help of a on the transport speed of the test object pulled clock signal will be the release of the Test station output test data and the periods, in which the paint spraying station applies a paint injects the test specimen, controlled so that in one adjustable section at the pipe end the test data output is blocked, and that in the sections mentioned a color application takes place. Depending on the particular Type of device under test can be sawed off later Adjust the length of the end sections. You get  So tested metal pipes or rods, each because they have a recognizable marking, which facilitates the further processing of the parts a mini for each type of test object painter committee is achieved.

The following is an embodiment of the invention explained in more detail with reference to the drawing.

The only figure shows a schematic diagram of a device for zer trouble-free testing of metal pipes and rods in connection with a paint spray station to the Markie of the tested pipes.

Along a transport path represented by a dash-dotted line St , a test specimen 1 is transported at a defined speed in the direction of arrow B , which is to be a steel tube.

A measuring section 2 , which contains, for example, two light barriers 3 and 4 , supplies a pulse when the front end Ve of the tube 1 passes, which pulse is converted by a clock generator 5 into a clock pulse train Cl . The frequency of the clock pulse train Cl thus depends on the transport speed of the tube 1 .

Next, on the transport path St there is a pipe start / pipe end detector designed, for example, as a light barrier 6 . The output signal of the light barrier 6 is given to a pulse generator 7 , which generates from the signal supplied to it a pulse RA characterizing the start of the tube and a pulse RE characterizing the tube end.

The light barrier 6 is followed by a test station 8 , in which the pipe 1 is tested in continuous operation. The test station 8 is e.g. B. an ultrasonic test station with a test head 9 , which occupies a predetermined position along the transport path St. The special details of such test facilities are known per se and are not explained in more detail here. The test station 8 outputs test data at the data output DA .

The period in which the test station 8 delivers usable test data at the output DA is controlled by a control device which generates a signal “test data release” PDF and a signal “test data lock” PDS .

The test station control device contains two presettable counters 10 and 11 . The clocked by the clock signal Cl counter 10 starts the counting operation upon receipt of a tubular top characterizing signal RA. The counter is preset to a value d 1 + Δ A. This value d 1 + Δ A is a number which, in the form of counting pulses Cl, represents the distance d 1 between the light barrier 6 and the test head 9 , plus a certain value A , which corresponds to the masking for the beginning of the pipe, ie later Pipe section to be cut off at the beginning of the pipe, which does not provide error-free test data.

When the presettable counter 10 reaches the counter reading zero, it sends the signal PDF to the test station 8 , which then outputs test data at the output DA . Due to the above-mentioned counter presetting, the PDF signal appears precisely when error-free test data are obtained.

The preset counter 11 is set to a value d 1 - Δ E. Δ E corresponds to the blanking at the end of the pipe. The counter 11 is started with the signal RE characterizing the pipe end. When the counter reading reaches zero, the signal PDS is generated, so that the output of test data is ended a certain distance E before the end of the pipe.

A paint spraying head 12 with an associated control unit is located below the horizontal dashed line drawn in the figure. The nozzle of the paint spraying head 12 has a defined distance d 2 from the test head 9 of the test station 8 , and a defined distance d 3 from the light barrier 6 .

During the duration of a signal SA given to the paint spray head 12 and during the duration of a signal SE , the paint spray head is activated in order to spray a paint application onto the front and rear end section of the tube 1 under test.

The control unit for the paint spray head 12 comprises four presettable counters 13, 14, 15 and 16 as well as two SR flip-flops 17 and 18 , which generate the signals SA and SE mentioned at its Q output. The presettable counters 13-16 are the same as the presettable counters 10 and 11 of the test station control device.

The value d 3 is preset in the counter 13 and the counter starts the counting process with the signal RA . When the counter reading reaches zero, the flip-flop 17 is set, as a result of which the signal SA appears at its output Q. The paint spraying head 12 thus begins to eject paint exactly at the point in time when the front pipe end VE has reached the height of the paint spraying head 12 , that is to say after it has passed the light barrier 6, the distance d 3 .

The value d 2 is set in the counter 14 and the counter is started with the signal PDF . It is hereby achieved that the flip-flop 17 is then reset and the signal SA is then ended when that point of the tube 1 passes the paint spraying head 12 at which the test data was released at the beginning of the tube.

The value d 2 is also set in the counter 15 and the counter is started with the signal PDS . Here, the flip-flop 18 is set at exactly the time to generate the spray head 12 activating Si gnals SE , at which the pipe 1 passes the paint spray head 12 at that point on the pipe at which the test data lock occurs at the pipe end. The counter 16 is preset to the value d 3 and started with the signal RE . This ends the paint application at the end of the tube.

In the embodiment of the invention described above, the unusable section at the beginning of the pipe and the section at the end of the pipe were marked with the aid of the paint spraying head 12 and the associated control unit. However, the control unit can also be designed in such a way that the two unusable end sections of the tube remain without paint application and instead only the intermediate section, that is the tested, usable section of the tube, is marked. However, this variant is much less favorable with long pipes than the embodiment described in more detail above.

The color is preferably a fluorescent color used by a suitable detector automa table can be recognized, so that the recognized tube sections at the beginning and end of the pipe automatically can be sawed off.

To the device shown in the drawing a microprocessor, not shown, is connected be, with the help of minimizing the unchecked and with start and End sections are done. Data can be stored in a memory regarding the specimen geometry, the system geometry and the test speed can be saved. These Data is either previously stored in the memory have been or are entered if necessary. Based on that The microcomputer determines this data by means of a ge suitable program the cheapest (minimized) Dimensions for the start and end sections, which are assigned a test data lock.

The data determined by the microcomputer are then passed on to the device shown in the figure. In particular, the presettable counters 10 and 11 are preset using the minimization data.

• 1 pipe
  2 measuring section
  3, 4 light barrier
  5 clocks
  6 light barrier
  7 pulse generator
  8 test station
  9 test head
  10, 11 presettable counters
  12 paint spraying head
  13, 14, 15, 16 presettable counters
  17, 18 SR flip flops
  VE tube front end
  Cl working clock signal
  RA pipe start
  RE pipe end
  St transport route
  DA data output from 8
  PDF test data release
  PDS test data lock
  d 1 = distance between 6 and 9
  d 2 = distance between 9 and 12
  d 3 = distance between 6 and 12
  Δ A = blanking of pipe start
  Δ E = blanking of pipe end
  SA = spray command pipe start
  SE = spray command pipe end

Claims (7)

1.Procedure for the non-destructive testing of pipes and rods made of metal, in which the test specimen is moved at a defined speed along a preferably straight transport path through a test station, which provides the test data of the test specimen which is faulty at the start and end point of the test specimen can, which is why a test data lock occurs for these sections, e.g. B. in such a way that the test data is prevented from being output by the test station, characterized in that the beginning and the end section or the intermediate section of the test object are automatically provided with a marking. 2. The method according to claim 1, characterized ge indicates that the marking from egg paint application in the sections or in the section consists, in particular, of an order from fluores decorative color. 3. The method according to claim 1 or 2, characterized characterized in that marking the DUT takes place after the DUT enters the test station has gone through 4. Device for performing the method according to one of claims 1 to 3, characterized in that the test station ( 8 ) - seen in the direction of movement of the test object - a pipe start / pipe end detector ( 6, 7 ) upstream and a paint spraying station ( 12 ) for marking the test object ( 1 ) is connected downstream that a test station control device ( 10, 11 ) is provided for releasing and blocking the test data output by the test station ( 8 ), which is based on those of the detector ( 6, 7 ) generated pulses (RA, RE) , to preset values (Δ A , Δ E) for the lengths of the start and end sections of the test object ( 1 ) and to a set value for the distance (d 1 ) between the detector ( 6, 7 ) and test station ( 8 ) responds to signals (PDF, PDS) for releasing or locking the test data generated, and that a control unit ( 13-18 ) for the paint spraying station ( 12 ) is provided, which generates those generated by the detector Pulses (RA, RE) from the test station control er device ( 10, 11 ) generated signals (PDF, PDS) and distance values for the distances (d 1 , d 2 , d 3 ) between the detector ( 6, 7 ) and test station ( 8 ), test station ( 8 ) and paint spray station ( 12 ) and detector ( 6, 7 ) and paint spray station ( 12 ) receives. 5. The device according to claim 4, characterized in that on the transport path (St) a measuring section ( 2, 3, 4 ) for obtaining a speed of the test object ( 1 ) dependent Ar beitstakt is arranged, and that the test station control device ( 10, 11 ) and the control unit ( 13-18 ) receive the working clock signal (Cl) . 6. The device according to claim 5, characterized in that the control device ( 10, 11 ) and the control unit ( 13-18 ) each have a plurality of presettable counters which are clocked by the working clock signal (Cl) and in which the different values be preset, which are counted down to zero in response to an enable signal (e.g. RA, RE) in order to generate zero control output signals when the count is reached. 7. Device according to one of the preceding An sayings, characterized in that a computing device is provided, which the unge checked and initialized with a test data lock and end sections depending on the test object geometry, the system geometry and / or the test ge speed minimized.