JPS60106672A - Automatic multilayer welding - Google Patents

Abstract

PURPOSE:To eliminate defects that occur when the width of weaving is large by making welding of plural passes of proper number for each layer using straight welding and weaving welding or weaving welding of the second layer and after. CONSTITUTION:A round of welding is taken performing straight welding for the first layer A of the bottom. Multipass welding is made for the second layer and after. However, for the second layer, both sides B, C are straight welded successively. For the third layer and after, sides, D, G, J, M on the nozzle 2 side are straight welded first, and sides E, H, K, N of base tube 1 side are welded by minute weaving keeping the height of the welding torch at that time, and welding is made accurately correcting by an arc sensor. Intermediate parts F, I, L, O, P between them not yet welded are welded by ordinary weaving welding.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a welding method for automatically performing multilayer welding of a groove using an automatic welding device such as a welding robot.

[Prior art]

When automatic multi-layer welding of V-shaped, J-shaped, or diamond-shaped grooves is performed by a welding robot, it is comparatively easy to use conventional copying control.
Like No. 82, most of the welding was done using a one-layer, one-bus method. In addition, the above-mentioned one-layer l-bus method means that for each layer of the m-connection layer,
The first NI Gostrade welding is performed on the bottom, and each layer after the second layer is weaved one time with the weaving width gradually increasing, thereby performing pass welding for each layer. However, this welding method has fJ problems such as 01 order, so the range of application is limited, such as the welding work being specified, and it is not common. [Ge] As the weaving width increases as the weaving width approaches the final layer, the heat generated by the weaving increases, and the effects of this heat degrade welding performance and the quality of the finished product. (Note) If the weaving width is wide, the molten metal will come out and the finish will be poor, but it may also become impossible to fuse.Especially if the weaving width is three-dimensional, where the bevel tangent is not flat but sloped. (c) Also, since the heat input during welding is large, the welding current is suppressed to a low level, which is not efficient. (Purpose of the Invention) As described above, the conventional multi-layer automatic welding method using the one-layer, one-bus method has various problems in practical use. To solve the drawbacks?The present invention was devised as a technical problem, and it is possible to automatically perform multi-layer welding using a bath welding robot, etc., which is equivalent to that performed manually by a skilled welding engineer. The present invention has the following points: By making the device Q easily applicable, there are no restrictions on the form of groove welding and welding posture, and the scope of welding can be expanded, thereby promoting automatic welding. (Structure of the Invention) The present invention is characterized in that the groove is automatically welded in multiple layers by lNN multiple passes, and the first layer at the bottom is welded in one pass, and the next layer is ζ Go 2 buses, 3 buses or G after the 3rd layer
@L Is it better than that? 1. When aligning, the welding baths on both sides along the base metal surface at the groove are first applied, and then the welding baths are transferred to the welding baths on the intermediate part sandwiched between the two sides. Straight welding or slight weaving bath welding is performed for each welding bath in the middle section based on commands from a positioning sensor installed corresponding to the welding torch. ) 8 If (The weaving width of the unwelded part and Determine the position. If this weaving width is within the allowable weaving width, perform weaving welding in one pass, while if it exceeds the Ff weaving width 2, weave welding multiple buses with the smallest number. It is possible to reduce heat input by using a multi-gas method.
The position to be directed to the welding torch and the weaving width can be accurately and easily determined, making it possible to perform well-organized multi-layer welding, thereby achieving the intended purpose.

【Example】

FIG. 1 is a diagram schematically showing a welding robot according to the method of the present invention and a workpiece to be welded. The nozzle (21) is joined at right angles to the axis, and has a structure in which the nozzle (2) is orthogonally branched from the main pipe (1), and the intersecting curve formed at the intersection part The saddle-shaped welding line (31 is automatically welded and integrated by the welding robot. The sloping surface formed by the peripheral surface of the hole in the part forms a bevel-shaped bevel, and there is also a slope in the IC three-dimensional closed curve. The Ro axis rotates around the circumference, !2, and the nozzle (two axes that move up and down parallel to the central axis of 21, and the two axes that move up and down parallel to the center axis of 21, and the horizontal linear movement that can move toward and away from the outer peripheral surface of the nozzle + 21 orthogonal to the zill). A welding torch +41 is provided at the tip of the main body having three axes including the X-axis, and the welding torch (41)
The torch shaft of the nozzle (21) has an S-axis at its tip that can be swung in the vertical direction so that the angle of inclination to the center axis of the nozzle (21) can be changed. To automatically perform multi-layer welding on the groove in step 3), operate the Ro, Z, However, the welding bus along the vertical surface on the nozzle 21 side is a contact type positioning sensor such as a copying stylus 15 that is brought into contact with the circumferential surface of the nozzle 21. On the other hand, the welding bath along the inclined surface of the hole periphery of the main tube fil is controlled by a current-controlled positioning sensor, such as an arc sensor (not shown), which is carried out in combination with weaving bath contact. ] The position can be corrected by detecting the current. By the way, it goes without saying that accurate positioning of the bath welding torch +41 is necessary to stabilize the arc generated. Accurate information must be taught in advance to the robot's data bank. Therefore, as shown in Figure 2, the bottom of the groove ■, the upper end @ of the slope side, and the excess thickness of the vertical side. By first teaching the data bank the considered predetermined position ○, it is possible to intertwine the welding position O on the slope side with the previous weld layer detected by the arc sensor and the taught upper end @ position. The height can be detected by a height detection sensor (not shown) at that height.Next, method 2 for performing multi-layer automatic welding will be described in detail with reference to Fig. 3. The position of &G can be determined from the information regarding (■) above, so once the position is determined, straight welding is performed and the first layer bath welding is completed. From the second layer onwards, G-go multi-pass bath welding is performed. , First, for the second layer, it is sufficient to make straight bath contact on both sides [BI
After straight welding first, use the bath welding torch (
While maintaining the height of 41, side i lK on the main tube ill side.
J's 1 fKI +NJ is micro-weaved and welded at an accurate position while being corrected by an arc sensor. Since the third layer and subsequent layers have a wide G bath width, even if both sides are welded, there will be an unwelded part in the middle part sandwiched between them.
IcII[Pl is bath welded by conventional weaving welding means. In this case, the width and position of the weld bus in the unwelded part can be determined by calculating the groove part of each layer from the groove shape taught in advance and subtracting the width of the welding pass on both sides from this. So. Weaving width and voltage of this intermediate welding pass. All you have to do is retrieve welding conditions such as current and speed from the data bank, output them, and perform welding. By the way, the weaving width in the middle part Ud of the 5th layer and onwards can be made as wide as possible (so if it is wider than the allowable weaving width determined by the amount of heat per person, the slope of the groove, etc., we will use 2 passes, 3 passes, etc.) , performs weaving welding in multiple passes with the minimum number of welds.In this way, automatic welding using the single-layer multi-bus method can be performed accurately, eliminating undesirable phenomena such as flow of molten metal and blowholes. Accurate and well-organized multi-layer welding is possible. Note that the above embodiment relates to a welding method for a wedge-shaped groove, and in the case of a V-shaped groove in which both sides are inclined surfaces, both sides are welded. (Effects of the invention) As is clear from the above description, according to the uninvented method, each layer is welded by straight bath welding and weaving welding or by weaving welding after the first and second layers. Since welding is performed using an appropriate number of multiple nozzles per weld, it is possible to narrow the welding width and reduce heat input, which prevents molten metal from flowing and reducing welding efficiency. It is possible to eliminate the drawbacks that occur when the weaving width is wide.Moreover, according to the present invention, each welding bus on both sides of the G groove is preceded by a command from a positioning sensor, and this surface welding path is followed by a command from a positioning sensor. Since the weaving welding of the sandwiched intermediate part is performed continuously, the weaving width can be calculated and controlled accurately and easily.In this way, the multi-layer welding of the G11 multi-layer weld of the present invention is possible. By performing automatic welding, it is possible to weld grooves with slopes, and the range of welding work is expanded, which plays a role in promoting automatic welding, and has great practical value.

[Brief explanation of drawings]

FIG. 1 is a schematic mechanical diagram of a welding robot that implements the method of the present invention, and FIGS. 2 and 3 are sectional views of a groove portion for explaining the method of the present invention. (4)...Welding torch.

Claims (1)

[Claims] 1. A method in which multi-layer automatic welding of the groove is performed in multiple passes for each layer, and for each layer from the second layer onwards, excluding the first layer at the bottom, each welding pass on both sides along the base metal surface is performed. After the preceding welding, the process moves to each welding pass in the intermediate part between the two sides, and for each welding pass on both sides, straight welding is performed based on a command from a positioning sensor provided corresponding to the welding torch. Alternatively, by performing minute weaving welding, for each intermediate welding pass, calculate the groove middle of each layer from the groove shape taught in advance, and subtract the width of the welding pass on both sides from this. Determine the weaving width and position of the unwelded part, and if this weaving width is within the allowable weaving width, perform Epass weaving, -
1. A multilayer welding automatic welding method characterized in that if the weaving width exceeds an allowable weaving width, weaving welding is performed using the smallest number of multiple passes.