Welding assessment during welding process

Abstract

To assess a butt welded part of a plastic pipe or joint in a welding device.SOLUTION: A method of assessing a welded part comprises steps of: fastening and positioning a pipe end to be welded to a welding device so as to be opposed to an end surface; autonomously positioning or adjusting an inspection head on the basis of a pipe parameter for detecting the pipe end; inspecting prescribed regions provided on both pipe ends by using at least one first sensor arranged in the inspection head; assessing inspection data obtained on the basis of a prescribed value; inspecting the end surface of the pipe end by using a second sensor using a different inspection method from that of the first sensor; assessing inspection data obtained on the basis of the prescribed value; and executing a welding process including recording of the welding process. The method performs the final assessment of the welded part on the basis of the obtained inspection data and recorded welding process.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for evaluating butt welds of plastic pipes or fittings in a welding device, as well as a system including a welding device, an inspection device with an inspection head having two sensors, a control device, and a memory, the method comprising: - clamping or fixing the pipe ends to be welded in a welding device with their end faces facing each other; - autonomously aligning or adjusting the inspection head based on the tube parameters to then detect the tube end; - inspecting predetermined areas on both tube ends using at least one first sensor arranged in an inspection head; - evaluating the determined inspection data based on predetermined values; - inspecting the end face of the tube end with a second sensor that uses a different inspection method than the first sensor; - evaluating the determined inspection data based on predetermined values; - performing a welding process, including recording the welding process; The present invention relates to a method and system comprising: [Background technology]

[0002] Inspection of butt welds serves to ensure the quality of the weld. It is not important which method is used to butt weld the pipe or fitting: it can be non-contact infrared welding, classic butt welding with a heated mirror, or another method. Depending on the pipe or fitting to be welded, i.e., its dimensions, its plastic, the welding technique used, etc., the weld seam must have a certain shape or size that can be visually inspected, and this is the basis on which welds have been inspected up to now. Therefore, there are guidelines and standards that define in detail what the seam must look like and what the acceptable dimensions should be in relation to the pipe or fitting characteristics and weld characteristics in order for them to meet the requirements.

[0003] Furthermore, it is known to use ultrasonic testing to inspect such weld seams in order to check their structure, but ultrasonic testing is performed after the weld seam has completely cooled, which requires the welded ends to remain clamped in the welding device for a certain period of time before ultrasonic testing of the seam can be performed.

[0004] Up to now, manual visual evaluation and ultrasonic testing have mostly been carried out by skilled craftsmen who compare, inspect and then evaluate the resulting weld seams based on known standards and guidelines, with the drawback that the evaluation by the skilled craftsmen is very time-consuming and therefore very expensive, also depending on the cooling time of the weld seam.

[0005] From EP-A-3 550 256 and EP-A-2 963 380 methods for inspecting weld seams are known, in which the geometry of the weld seam is inspected purely optically by means of a sensor.

[0006] An apparatus and method for ultrasonic inspection of butt-welded seams in plastic pipes is known from EP 3816621. Here too, the disadvantage is that the seam must first be completely cooled before such an inspection can be carried out, which is very time-consuming and therefore makes such an inspection by a corresponding specialist operator very expensive.

[0007] Furthermore, special equipment must be used for each inspection, which in turn requires a lot of time to set up and a lot of equipment that must be brought to the location or construction site where such welding is to be performed. Summary of the Invention [Problem to be solved by the invention]

[0008] It is an object of the present invention to provide a method and system for evaluating butt welds that allows the weld or weld inspection to be performed more inexpensively and yet provides a reliable evaluation or assessment, thereby saving time and manpower. [Means for solving the problem]

[0009] This problem is solved according to the invention in that the final evaluation of the weld is carried out on the basis of the determined inspection data and the recorded welding process, and the inspection head comprises two sensors, which have different inspection methods.

[0010] A method according to the present invention for evaluating butt welds of plastic pipes and fittings in a welding apparatus includes the following steps: The pipe or fitting ends to be welded are clamped or fixed in position in a welding device, with the end faces of the pipe or fitting end positioned opposite each other. The inspection head is then autonomously aligned or adjusted based on the pipe parameters, so that the pipe ends can then be detected for inspection. Using the inspection head or at least one first sensor arranged in the inspection head, predetermined areas on both pipe ends are inspected. The determined inspection data are then evaluated and assessed based on predetermined values. The determined inspection data is preferably evaluated based on an algorithm that, based on calculations and evaluations, defines a predetermined area as good or unsatisfactory for welding. If an area is determined to be unsatisfactory, the pipe end piece can be cut, for example, and an inspection can then be performed on a new area. If the assessment is good, the method can be continued. The predetermined values ​​for the assessment, as well as the algorithm used, are preferably stored in a control device or its memory. In this case, the predetermined values ​​serve as comparison values ​​for the inspection data calculated using the algorithm or for assessing whether the area is good or unsatisfactory. Advantageously, the values ​​are repeatedly compared, adapted, and supplemented with new empirical values, in which case the control can be performed autonomously or data can be entered manually. Furthermore, it is advantageous if the values ​​or other data for the method according to the present invention are stored on the cloud or in another external, distributed storage location. Furthermore, the end face of the tube end is inspected using a second sensor that uses a different inspection method than the first sensor. Preferably, the end face of the tube end is first planed to obtain a clean, flat surface before the inspection, and then an optical inspection is performed. Again, the determined inspection data is evaluated or calculated using an algorithm, and an assessment is made based on predetermined values ​​or the suitability for welding is evaluated. As with the initial inspection, this is performed by comparison with stored values, which are preferably also repeatedly compared and supplemented. If the previous inspection, in each case, indicates that the tube end is suitable for welding, welding can be performed.It has been found to be advantageous to similarly optically inspect the welding mirror used to heat the tube end before use, preferably using a second sensor. This step also prevents contaminants from being introduced during welding. The performed welding process is recorded by a system or control device, which can determine whether the process was performed correctly and whether all boundary conditions were met. For this purpose, the welding time, welding temperature, welding pressure, and applied welding energy are preferably monitored and recorded. Alternatively, other data, such as the ambient temperature, can also be monitored and recorded. In this case, the welding data is also included in the final evaluation of the weld. After welding, a new evaluation of the weld is performed using an algorithm based on the determined data. For the final evaluation of the weld, the previous inspection data and the recorded data of the performed welding process are evaluated using an algorithm to determine whether the weld seam is good or unusable.

[0011] The evaluation of the weld is advantageously based on an algorithm that takes into account the obtained inspection data and the recorded welding process or that is used in the calculation. The algorithm incorporates inspection data obtained from at least a first inspection and a second inspection by ultrasonic inspection of the predetermined area and optical inspection of the end face. Furthermore, the algorithm includes recorded data on the welding process or its components, preferably data on the welding temperature and welding time. It is advantageous to check the texture of the tube by inspecting a predetermined area on the tube end with a first sensor. The inspection of a predetermined area on the tube end with a first sensor checks the texture of the tube before the welding process. Since many poor welds are due to the presence of material defects, such as inclusions, defects, and contaminants, already present in the tube end in the area of ​​the weld zone, defects can already be avoided by inspecting the texture of the tube wall in the predetermined area before welding.

[0012] Advantageously, the welding device has a control device and a memory for data processing, and the inspection device can also be adapted to the welding device, the inspection device having a control device and a memory for data processing.

[0013] It has proven advantageous to inspect a predetermined area of ​​the tube end using sound waves, preferably ultrasonic waves, to determine whether the tissue has inclusions or other contaminants that would weaken the weld seam or cause it to no longer meet requirements.

[0014] Preferably, the second sensor is an optical sensor, which optically inspects the end face of the tube end. The end face is inspected for dirt, damage, or other criteria that could damage the weld. The second sensor is preferably also arranged in the inspection head and preferably serves to align or adjust the inspection head with respect to the tightened tube end. The optical sensor is preferably configured as a photosensitive sensor, particularly preferably as a camera.

[0015] According to a preferred embodiment, the predetermined areas on both tube ends are spaced apart from the end faces and correspond to the welding zones that will be heated for welding. Since the very front end areas of the tube ends often have dirt and do not have a flat surface, these very front end areas are planed, so the predetermined areas that should be inspected are spaced apart or offset from the end faces because, after planing of the end faces, these areas will come into direct contact with the heating mirrors and become the welding zones.

[0016] The method according to the present invention is preferably characterized in that the clamped tube end is detected by the welding device or the inspection head to determine the tube parameters, by scanning the tube end, a bar code, or by manually entering the tube data. Advantageously, an optical sensor in the inspection head can autonomously detect the tube end based on its size and color or by bar code detection. This can also be done by a separate sensor connected to the control device.

[0017] According to another preferred embodiment, a predetermined area at the tube end is also optically inspected, preferably by a second sensor. In addition to the textural inspection, preferably by ultrasound, it is advantageous to also optically inspect this area, since significant contaminants may be present on the surface, which would be detected by optical inspection and could have a negative effect on the weld.

[0018] Another advantageous embodiment shows that after the welding process, the formed weld seam is inspected, preferably with ultrasound and / or a camera, before it cools and while the tube end is still clamped to the welding device. This, on the one hand, allows another inspection, and, on the other hand, does not result in significant time losses, since the inspection is carried out in the welding device immediately after the welding is performed. No waiting time for the weld seam to cool is required, and the structural inspection of the weld seam can be carried out immediately after the welding.

[0019] The object is also achieved by the system for assessing butt welds on plastic pipes or fittings, which includes a welding device for welding the plastic pipe or fitting end on its end face, an inspection device, a control device, and a memory, wherein the inspection device has an inspection head in which at least two sensors are arranged, the sensors having different inspection methods or being based on different inspection technologies.

[0020] The inspection device can be retrofitted to an existing welding device and may be readily integrated into the welding device, which is advantageous with respect to the controller and memory, because in this case, if the system has a controller and memory and the inspection device is retrofitted, the welding device and the inspection device will have a controller and memory, and these controllers and memories can be synchronized, or only one of the welding device and the inspection device can have a controller and memory, and the other device can be connected to its controller and memory.

[0021] Preferably, the inspection head includes an optical sensor and an acoustic sensor. This allows a first inspection of a predetermined area for inspecting the tissue, and the acoustic sensor is used for this purpose. The optical sensor then checks the surface of the end face of the pipe or fitting to be welded. The optical sensor can also be used for other inspections or detections, as described in the method description. Of course, additional sensors can be incorporated into the system to perform other checks or detections.

[0022] It is advantageous for the first sensor to be an ultrasonic sensor and the second sensor to be a photosensitive sensor, preferably a camera. The first sensor detects tissue and possibly contaminants and evaluates them using an algorithm. Based on this first inspection, a predetermined area is then selected for suitability for welding, as described above with respect to the method. Similarly, the inspection data detected by the photosensitive sensor is evaluated using an algorithm to determine whether the inspected area is suitable for welding. This early inspection of pipes and fittings allows pipe ends and fitting ends that do not meet requirements to be detected and correspondingly removed before welding. This significantly reduces time, since welding is rarely performed on substrates that already do not meet requirements and are therefore unusable. Inspecting pipe and fitting ends before welding significantly reduces weld defects, since most weld defects are caused by poor starting material, which can be avoided or removed before welding.

[0023] In a preferred embodiment, the inspection device is integrated into the welding device, so that, as mentioned above, everything can be performed by the same control device, and the inspection head can be optimally positioned within the welding device.

[0024] All features are freely combinable with one another, and method features can be used for system features and vice versa.

[0025] The present invention will be described below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. [Brief explanation of the drawings]

[0026] [Figure 1] 1 shows a schematic arrangement of the components of the system according to the invention and a schematic diagram of the steps of the method according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0027] The diagram shown in FIG. 1 illustrates the general steps of the method according to the present invention and a schematic diagram of the components of the system according to the present invention. In step A, it can be seen that the inspection head 1 inspects or scans a predetermined area 5. Before this step, the tube end and / or fitting end 4 to be welded is clamped in a welding device (not shown). The end faces 6 of the tube end or fitting end are aligned so that they face each other. The inspection head 1 then adjusts itself based on the clamped tube end 6 or autonomously navigates to the desired position. This is achieved by the device's control device detecting the clamped tube end 6 or tube parameters, which can be detected by code detection, manual input, or by detecting the tube itself based on dimensions, color, etc. Based on the values ​​stored in the control device, the inspection head 1 autonomously adjusts itself. The predetermined area 5 of the tube end 6 is then inspected or scanned by a first sensor 2 in the inspection head 1, which is preferably configured as an acoustic sensor, or more preferably as an ultrasonic sensor. The inspection data is then evaluated using an algorithm that allows the area to be assessed as sufficient or insufficient for welding based on the inspection data. If the area is assessed as sufficient, step B is carried out. In this step B, the surface of the end face 6 of the tube end is inspected, preferably by a second sensor 3 also arranged in the inspection head 1. Naturally, the end face 6 is first planed down to the welding zone 5 corresponding to the predetermined area. For this purpose, an optical sensor 3 is used, preferably a photosensitive sensor, particularly preferably a camera. Here, too, the inspection data is subsequently evaluated using an algorithm that determines whether the end face 6 meets the requirements for the weld 7. If so, welding is performed; if not, the end face 6 can be reworked, for example. In step C, it can be seen that the tube ends 4 are already butted together. Naturally, these tube ends are first heated with a welding mirror (not visible), which allows the materials to be joined when they are butted together.The welding mirror can be checked again before the heating process with the optical sensor 3 or an additional optical sensor 3 to ensure that it does not reintroduce contaminants into the weld. Finally, in step D, the weld seam 7 must be detected after welding. This can be checked again with the acoustic sensor 2 and / or the optical sensor 3. Naturally, the welding process, i.e., time, temperature, etc., is also monitored, and this welding data is also recorded in the control device. Finally, a final evaluation of the weld is performed based on the first inspection data, the second inspection data, and the recorded welding data. This data is evaluated using an algorithm, which concludes that the weld is good or poor. All this data can be stored on the welding device, the inspection device, i.e., the system, or in a remote memory location. Furthermore, the data can be accessed and updated at any time using the control device and a portable operating unit. This can be done autonomously or manually. Furthermore, data exchange with other devices is also possible. [Explanation of symbols]

[0028] 1 Inspection head 2. First Sensor 3 Second Sensor 4 Pipe end / joint end 5. Predefined area / welding zone 6 End face 7 Welds / weld seams

Claims

1. 1. A method for evaluating butt welds (7) of plastic pipes or fittings in a welding apparatus, comprising: - clamping or fixing the pipe ends (4) to be welded in a welding device with the end faces (6) facing each other; - autonomously aligning or adjusting the inspection head (1) based on the tube parameters in order to then detect said tube end (4); - inspecting predetermined areas (5) on both tube ends (4) using at least one first sensor (2) arranged in the inspection head (1); - evaluating the determined inspection data based on predetermined values; - inspecting the end face (6) of the tube end (4) with a second sensor (3) that uses a different inspection method than the first sensor (2); - evaluating the determined inspection data based on predetermined values; - performing a welding process, including recording the welding process; In a method having and performing a final evaluation of the weld based on the determined inspection data and the recorded welding process.

2. The method of claim 1 , wherein a final evaluation of the weld is based on an algorithm that takes into account the determined inspection data and the recorded welding process.

3. 3. The method according to claim 1, further comprising checking the structure of the tube by inspecting the predetermined area (5) on the tube end (4) with the first sensor (2).

4. 2. The method according to claim 1, wherein the predetermined area (5) on the tube end (4) is inspected using sound waves, preferably ultrasonic waves.

5. 2. The method according to claim 1, wherein the second sensor (3) is an optical sensor, and optical inspection of the end face (6) of the tube end (4) is carried out using a preferably photosensitive sensor.

6. 2. The method according to claim 1, wherein the predetermined areas (5) provided on both of the tube ends (4) are spaced from the end faces (6) and correspond to the welding zones for the welding.

7. 2. The method according to claim 1, wherein the clamped tube end (4) is detected by the welding device or the inspection head (1), and the detection is performed by scanning the tube end (4), a bar code, or by manual input of the tube parameters.

8. 2. The method according to claim 1, wherein the predetermined area (5) on the tube end (4) is optically inspected, preferably by means of the second sensor (3).

9. 2. The method according to claim 1, wherein after the welding step, the resulting weld seam (7) is inspected once again before cooling and while fixed in position in the welding device, preferably by means of ultrasound.

10. A system for assessing butt welds of plastic pipes or fittings, preferably according to the method of claim 1, comprising a welding device for welding the plastic pipe end (4) or fitting end (4) on its end face side, an inspection device, a control device and a memory, wherein the inspection device has an inspection head (1) in which at least two sensors (2, 3) are arranged, A system characterized in that the two sensors (2, 3) have different inspection methods.

11. 11. The system according to claim 10, wherein the inspection head (1) comprises an optical sensor (3) and an acoustic sensor (2).

12. 12. System according to claim 10 or 11, wherein the first sensor (2) is an ultrasonic sensor and the second sensor (3) is a photosensitive sensor, preferably a camera.

13. The system of claim 10 , wherein the inspection device is integrated within the welding device.

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