JPH06510485A - Penetration control welding machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Penetration control welding machine Technical field The present invention relates to a welding machine that uses images of welding scenes to perform high-quality automatic welding. Ru. This welding machine is a penetration control type. In other words, the weld pattern that characterizes penetration Automatically correct parameters in real time.

Background technology Penetration is the depth to which the base metal melts during welding.

High-quality welds require molten metal throughout the thickness; Therefore, it is normal for a slight excess buildup (surface bulge) to occur on the back surface. child In addition, when overlay welding is performed, overlay is applied to the melted area, so welding It is normal for this to become the surface excess (surface bulge) of the bead that has been finished. in general The raised areas on the front and back sides and their widths are listed in the welded part acceptance specifications. It will be done. The present invention is TIG welding (inert gas welding using a tungsten welding rod) It is applied when making the weld bead using filler metal, and especially It is possible to vary the raised portions of the surface.

The invention can be applied to many fields, especially space engineering, nuclear power, aircraft, agricultural processing, etc. It can be applied to high-tech industry.

Welding parameters (regarding welding process, trajectory, etc.) in most automatic welding machines The welding procedure is systematically reproduced with the data adjusted to the design conditions, and then the actual welding process is performed. The method of recording and copying this regardless of the conditions is well known.

However, in actual production sites, welding conditions rarely remain constant. It is normal for unpredictable disturbances to occur, which may cause tolerances to be exceeded. Exceeding conditions may occur, resulting in defective products or returns.

However, taking these unpredictable disturbances into account, we are trying to minimize their negative effects. There are some devices that attempt to do so. Such equipment generally requires existing equipment. It has a built-in sensor that will be installed in the

G.M. Detriche (published by HERMES) J, M, DETRIcHE) “Welding Robot Sensors and Trajectory Consistency ( Robots de soudage, Capteurs et Adapta tivite de Trajectoire) J has the size of the equipment as mentioned above. parts are introduced.

In addition, Dee Havey (D, HARVEY) and Bea Lucas (B, L) UCAS) Both are 1 Welding Association Public Relations (Welding In5 titute Bu) The paper published in the June 1990 issue of J. It describes the control equipment. The device uses a video camera to record the waveform of welding current. It is possible to keep the melt penetration constant by adjusting the value to the desired value. be. The camera monitors the light level observed on the side facing the welding torch. The information is converted into a video signal by an optical lens that is sent to the camera via a video signal. like this The video signal obtained at the output of the camera is amplified and compared with the target value, which The desired depth of melting can be achieved.

The main drawback of the device is that the image is inverted, making it difficult to access the back side and There will be problems synchronizing the torch and camera.

Fortunately, the present invention ameliorates these disadvantages and automatically adjusts the weld penetration parameter. It can be adjusted dynamically and in real time.

Disclosure of invention The welding machine according to the present invention performs penetration control from the processing device that controls the welding head. do. This can be achieved by combining control by welding current and adjustment of arc voltage. In this way, weld penetration can be kept almost constant.

More precisely, the invention relates to a controlled welding machine incorporating - a constant arc; A power supply device for the joint, which guarantees voltage and constant welding current; - A control and processing device for obtaining a constant (appropriate) weld penetration, which includes the following: something that is characterized by i.e. - located at a measurable height relative to the weld area; For welding: The throat should be controllable in the height direction.

- On the one hand, the control and processing equipment to obtain a constant weld penetration is A device suitable for controlling the arc voltage to the first reference value. On the other hand, welding current control is used to control the surface bulge to a second reference value. Built-in equipment suitable for

In this specification, the height 1 of the r head refers to welding in a horizontal position, and in other positions, For example, when welding in an upward position, the contact plane between the head and the welding surface is It is clear that the distance between

Advantageously, the welding head is equipped with a device that shines a light spot on the welding area. . Furthermore, the head is equipped with a device for observing the weld area, and the observation device itself is At least one light spot suitable for determining the height of the welding throat from the above light spot position Consists of a position detector.

According to the present invention, the following are arranged in the device for controlling the height of the head. vinegar In other words, - a first human power section and a target receiving a first signal corresponding to the arc voltage to be measured; One comparator with a second input corresponding to a value, and an output.

- Input section connected to the output side of the comparator and a device for adjusting the height of the welding throat 1 x gutter height adjustment device with output side connected to.

Similarly, the following are arranged in the device for controlling the welding current.

That is, - a first input for receiving a first signal corresponding to the height of the object to be measured and a first signal corresponding to the target value; a second input for receiving a second signal, and one output. 1 unit.

- The input part connected to the output side of the comparator and the welding part that supplies current to the welding/nod. One current regulator with output connected to the generator.

Preferably, the device for observing the weld area includes a built-in imaging camera. Book According to one variant of the invention, the light spot positioning device is integrated with the camera. Ru.

On the other hand, the imaging camera is an image monitoring device suitable for remotely monitoring the status of welding work. It is equally desirable to connect the

Other features and advantages of the invention will be apparent from the description with reference to the drawings. It will become clearer. However, descriptions that refer to the drawings should clarify the explanation. The present invention is not limited to the present invention.

Brief description of the drawing The only drawing attached to this specification shows the actual welding with the welding head and processing equipment This is a schematic illustration of the machine.

BEST MODE FOR CARRYING OUT THE INVENTION The penetration control of the welding machine according to the present invention is based on characteristic parameters of penetration, e.g. Measure the ``back side raised part j'' of the weld bead to the ``surface raised part 1'' of the bead. The method is to control the welding current to a constant value by modifying the welding current according to the .

“Back side raised area” is the weld bead observed on the side facing the welding head. This refers to backside reinforcement, and is often used as a criterion for passing welding.

In reality, the surface bulge parameters are the welds extracted above the welding work site. It can be measured based on the measured value of the height of the pad. However, this measurement It is carried out when the condition that the arc voltage is controlled to a constant value is established. be. Adjustment of the arc voltage is carried out by adjusting the height of the welding head. It will be done.

Therefore, the existence of certain combinations of parameters is indirectly due to This is because the contact current varies depending on the height of the head, and also due to variations in the head height. This is because the arc voltage can be changed.

The correlation side (also simply referred to as r-relationship j in this specification) is determined between different parameters. Rukoto can. In order to make the correlation side usable from a control perspective, The correlation sides must have a one-to-l correspondence. In other words, it is a monotonous correlation and is null. The slope must not be too steep. There is a gap like this between the raised part on the back side and the welding current. There is a correlation side. The raised part on the surface and the raised part on the back of the above bead. A second correlation is established between .

Shown in the drawing is a welding machine according to the invention. The welding machine mainly uses a single welding machine. It consists of a contact head l, a plurality of processing units 2 and a single visual monitoring unit 3.

A welding torch 10 terminating in a welding head l welding rod 11 is built-in. The welding toe TIG type welding using a filler rod (using a tungsten welding rod) inert gas welding). The welding rod 11 generates an electric arc. The strength of the electric arc depends on the arc voltage and the welding torch 10. is a function of arc current.

The illumination device 12 can cast a light spot 13 over the entire weld area. Here weld area This is because the welding rod 11, the weld bead piece, and the joint part to be welded are It refers to a certain welding surface part. The device 12 for emitting a light spot is seen from the welding direction. It faces the front of the torch IO. The direction corresponds to the light intensity of the observation device (14 to 17). An angle of approximately 45° is optimal. If the angle is set like this, the welding part will be It is possible to optimally cast a light spot】3 over the entire area. In this way, welding The height of the pad can be measured using well-known triangulation methods.

Devices 14 to 17 for observing the weld zone are located in front of the welding torch 10, It makes it possible to visualize the area and measure some of its parameters. concerned The welding area observation devices 14 to 17 include an optical device 17 for visualization and a beam splitter. 15 and an imaging camera 14.

An image of the weld area is formed in the measurement chamber 16 by the beam splitter 15. . The chamber 16 has one or two position detection stations for detecting the position of the light spot 13. A line detector is installed. The position detector is a standard type and can observe the light spot 13. It has a structure that is easy to understand.

The height of the welding head is determined from the position of the light spot hitting the welding area using the above detector. I can do it.

An example is an analog position-sensing device (PSD) type circuit, where appropriate electronics are By combining this with the I know the location.

The imaging camera 14 is a CCD (charge-coupled device) type to prevent dazzle from light. , and is relatively unaffected by the strong electromagnetic waves that exist near the arc, resulting in high-quality images. You can get the image.

The output side of the camera 14 is connected to the visualization monitoring device 3 . The monitoring device 3 is According to this embodiment, it is monochrome. The first function of the monitoring device 3 is to The purpose is to allow the user to remotely monitor the weld area. Also, the second function Experimentally optimize the imaging conditions by Operate the light spot position detector under favorable conditions (i.e., outside the weld zone, no reflections, etc.). It becomes possible to

The light path starting from the light point emitting device 12 and the welding area observation devices 14 to 17 is transparent. It passes through the nozzle 18 through a clear window and is stored in the plate to be welded near the tip of the welding rod 11. bundle.

Furthermore, position measurements by the position sensing device (PSD) of chamber 16 are taken from the output side. The information is sent to a plurality of melting processing devices 2. The plurality of devices 2, on the one hand, It incorporates pressure control devices 20-22 and welding current control devices 23-25 on the other hand.

The arc voltage control devices 20 to 22 include an electronic comparator 21 (for example, a differential amplifier). is arranged, whereby the arc voltage base received at the input side E2 of the electronic device 21 is The reference value is measured by the welding torch 10 and received at the input side of the comparator 21. It is possible to compare the received arc voltage. On the output side S of the comparator 21 inputs the arc voltage error to the head height adjuster 20. I've already mentioned this This is because the arc voltage can be adjusted by adjusting the height of the head. The adjustment The output side of the device 20 is connected to a plurality of head height moving devices 22.

Similarly, the welding current control devices 23 to 25 include almost the same electronic device 21. An electronic comparison device 24 (differential amplifier) is provided, which allows the input side e2 to receive The input side of the comparator 24 is measured by the received height reference value and the light spot position detector. It can be compared with the height value received at e1. Output of the comparator 24 From the side S, the height error is transmitted to the current regulator 23. In other words, as mentioned earlier Second, it becomes possible to control the penetration by the welding current. This way you get The corrected current value is sent to the welding generator 25, which is the power source for the welding head. This will correct the current.

The head height, welding current, and arc voltage parameters are determined by the explanations below. It becomes easier to understand mutual control relationships between data.

The arc voltage mainly depends on the distance between the tip of the welding rod and the top of the surface bulge. Therefore, the first control to keep the arc voltage constant is to correct the head height. The control loop allows the head height to be measured to be directly a function of the surface protrusion. Rukoto can.

A second control loop, which maintains the surface bulge by modifying the welding current, This can serve the purpose of keeping the inset constant.

According to the embodiment of the present invention described above, it is possible to connect the cable to the entire welding machine. come.

However, it is not possible to program the entire or part of the welding process. By doing so, it is also possible to create a welding machine with the same functions.

Claims (9)

[Claims] 1. A controlled welding machine containing: - a welding head with a filler rod; (1), - multiple power supplies for the head ensuring constant arc voltage and constant welding current; Place, - Control equipment and processing equipment to obtain a constant (suitable and reasonable) weld penetration ( 2), which has the following characteristics: That is, - The welding head, which is located at a measurable height relative to the welding area, is controlled in the height direction. thing. - On the one hand, welding The first voltage control is performed by arranging automatic devices (20, 22) suitable for controlling the head height. control to a first target value and, on the other hand, control the resulting welding current. A suitable device (23, 25) is installed to raise the surface according to the second target value. This is the second control that controls the rear section. 2. Welding machine according to claim 1, comprising a device (12) for applying a light spot to the weld area. , 13) are arranged in the welding head. 3. The welding machine according to claim 1 or 2, further comprising: observing a welding area on the welding head. This device is characterized by being equipped with a plurality of devices (14, 17) for monitoring. 4. The welding machine according to claim 3, wherein the plurality of devices for observing the welding head include: A light spot position detector suitable for determining the height of the welding head based on the light spot position. It is characterized by having at least one internal unit. 5. A welding machine according to any one of claims 1 to 4, wherein the height of the welding head is controlled. A device characterized by having the following internally installed in multiple devices for controlling the device. i.e. , - a first input part (E1) for receiving a first signal corresponding to the arc voltage to be measured; a second input part (E2) receiving a second signal corresponding to the target value as well as an output part ( 1 comparator with S). - input section connected to the output side of the comparator and multiple welding head height correction devices; 1 head height adjuster with output connected to. 6. A welding machine according to any one of claims 1 to 5, for controlling a welding current. A device characterized by having the following items installed in multiple devices. That is, - a first input part (e1) and an eye receiving a first signal corresponding to the height of the object to be measured; a second input part (e2) receiving a second signal corresponding to the reference value and an output part (s ) with one comparator. – the input part connected to the output side of the comparator and the melt supplying current to the welding head; One current regulator with output connected to the generator. 7. A welding machine according to claim 3, wherein the welding machine comprises a plurality of imaging devices for observing the weld area. It is characterized by the deployment of a camera for 8. Welding machine according to claim 7, characterized in that the imaging camera (14) is configured for image visualization monitoring. A device characterized by being connected to the device (3). 9. 9. A welding machine according to claim 8, wherein the image visualization monitoring device monitors welding work conditions. A device characterized in that it is suitable for remote monitoring.