Showing papers on "Butt welding published in 1997"

Method of welding the ends of pipe together using dual welding wires

Abstract: A new system for welding sections of pipe together to form a long, continuous pipeline. A welding bug is mounted on a guide track which goes around the circumference of the pipe. The welding bug is provided with a wire feeder, a motor to drive the wire feeder, and driving motor for driving the bug around the track. One may vary the speed of the bug and the wire feeder while the bug is continuously driven around the track. The welding head on the welding bug is powered by a surface-tension-transfer power source. The initial or root pass is made external of the pipe. In one embodiment there is a dual welding wire feeder for driving two welding wires simultaneously at the same speed.

CO2 laser beam welding of 6061-T6 aluminum alloy thin plate

Abstract: Laser beam welding is an attractive welding process for age-hardened aluminum alloys, because its low heat input minimizes the width of weld fusion and heat-affected zones (HAZs). In the present work, 1-mm-thick age-hardened Al-Mg-Si alloy, 6061-T6, plates were welded with full penetration using a 2.5-kW CO2 laser. Fractions of porosity in the fusion zones were less than 0.05 pct in bead-on-plate welding and less than 0.2 pct in butt welding with polishing the groove surface before welding. The width of a softened region in the-laser beam welds was less than 1/4 times that of a tungsten inert gas (TIG) weld. The softened region is caused by reversion of strengthening β″ (Mg2Si) precipitates due to weld heat input. The hardness values of the softened region in the laser beam welds were almost fully recovered to that of the base metal after an artificial aging treatment at 448 K for 28.8 ks without solution annealing, whereas those in the TIG weld were not recovered in a partly reverted region. Both the bead-on-plate weld and the butt weld after the postweld artificial aging treatment had almost equivalent tensile strengths to that of the base plate.

Welding of thermoplastics reinforced with random glass mat

Abstract: Thermoplastics reinforced with random glass mat have high strength and stiffness ; the fibers dominate the mechanical behavior of these composites. The results of this investigation have shown that fibers are ineffective for reinforcing hot-tool and vibration welded butt welds. The maximum weld strengths attained with GMT are comparable to the strengths of good welds of the unfilled material. The optimum hot-tool welding parameters for the reinforced materials are different from those for the unfilled material. Unfilled polypropylene is easier to weld than unfilled polyamide. This characteristic is also true of the reinforced materials. In vibration welding, high welding pressures and high amplitudes result in lower mechanical properties. The optimum penetration depends on the fiber content of the bulk material. This penetration dependence is different from that for unfilled thermoplastic, for which the mechanical properties are independent of the penetration once a steady state has been attained.

Plant for friction stir welding

Abstract: A plant for friction stir welding, comprising a welding probe (12), a drive unit (13) driving the welding probe, a work table (7) supporting the workpiece or workpieces (2, 3) to be welded, and at least one clamping means (5, 6) for clamping the workpieces to one another and/or to the work table, or the workpieces to the work table, respectively, during the welding operation. The plant likewise comprises a milling tool.

Control method in multi-layer welding

Abstract: In a multi-layer welding, weld line and a gap width of workpieces (A, B) to be welded are detected by a laser sensor mounted on a robot, during a welding for a first layer, whereby, a welding torch mounted on the robot is made to follow the weld line and welding conditions are adjusted in accordance with the detected gap width. The detected gap width is stored in the storage means together with the weld line data. Then, weldings for a second and subsequent layers are performed by using the stored data in such a manner that the welding torch is made to follow the weld line, and the welding conditions are adjusted in accordance with the gap width.

Apparatus for weld head to pipe joint alignment for welding

Abstract: An improvement to orbital welding heads and welding systems for welding pipe and tubing butt joints, consisting of a removable or retractable detector module in the welding head for sensing the proper alignment of the welding head to the pipe joint prior to welding. The module contains a light source that shires a light beam on the pipe wall, and a detector with associated circuitry and output indicators to signal when the reflected light is interrupted by the presence of a seam or pipe joint. The module may be in the form of a battery powered module that with the use of sleeves fits into the viewing port of a variety of welding heads, or it may be an integral capability that retracts into the side of the weld head out of the way of the welding tip orbiting mechanism. The improvement extends to an automated traversing capability of the welding head along the pipe, in concert with the alignment sensor capability, to provide automated location and clamping of the weld head in the correct position of alignment for welding.

Microindentation testing of inhomogeneous microstructures in welded polyethylene

Abstract: A microcomputer controlled microindenter with a flat cylindrical microindenter face has been used to measure the variation of storage modulus and loss factor that results from differences in microstructure in high density polyethylene (HDPE). The microstructural variations have been produced by butt welding the polyethylene and varying the thermal histories of the weld. The dynamic mechanical thermal analysis data from the microindenter have been compared to similar tests on uniform bulk material run in bending using a commercial analyzer. The normalization procedure used on the microindenter data was justified by examining the calculated stress fields under the indenter tip. The quantities measured using the microindenter are consistent with the measured changes in crystallinity.

Method and apparatus of removing liquid from underground cavity by directional drilling

Abstract: Underground cavities containing liquid contaminants are remediated by drilling directionally through the cavity and then pulling back pipe with a slotted section extending through the cavity. The pipe is supplied on reels in lengths much longer than in the prior art, thus avoiding the joining by butt welding of successive short lengths of pipe as in the prior art. Slots are preferably cut parallel to the axis of the pipe or at a angle in respect to the axis instead of being cut radially as in the prior art, so that a much greater portion of the pipe circumference remains joined together, thereby substantially increasing the axial strength of the pipe.

The hot‐tool and vibration welding of acrylonitrile‐butadiene‐styrene

Abstract: Thermoplastic window frames are made by hot-tool welding mitered, extruded profiles. The effects of weld process conditions on the strengths of hot-tool butt joints are investigated for a grade of acrylonitrile-butadiene-styrene that was specially developed for window-frame applications. Vibration-weld strength data, obtained on a research machine in which all the process variables can be independently controlled, are used to benchmark strengths of hot-tool welds made on a commercial welding machine. Process differences between hot-tool butt welding and the hot-tool welding of mitered, extruded profiles are discussed.

Friction stir welding of aluminium plate

Abstract: Summary Friction stir welding is a novel welding process which is a solid state butt welding process for sheet or plate using the friction phenomenon. This paper describes the effect of the rotation speed of the stir rod and the plate traverse speed during the friction stir welding process on the quality of welded joints. It was found that aluminium plates could be joined without defects by this process and that good joint properties were achieved using proper welding conditions for the rotation speed of the stir rod and the traverse speed. Hardness of the joint was reduced and its joint efficiency was 90% that of the base metals. Microstructures of friction stir welded joints were similar to those of friction welded ones, that is, fine grained structures.

Brace joining structure

Abstract: PROBLEM TO BE SOLVED: To eliminate the need for butt welding and reinforcement of the internal part of a steel pipe and to ensure strength through the execution of a simple work by a method wherein a plate is fillet welded to the side of a square steel pipe pole, and a brace material is joined to the extension part of the plate. SOLUTION: In a structure wherein a brace material 13 is arranged in a frame surface surrounded with a square steel pipe pole 1 and a beam and joined therewith, plates 14 and 14 are fillet welded to a side paralleling the frame surface of the square steel pipe pole 1. A brace material 13 is joined with an extension part 4a extending in the frame surface of the plate 14. In this case, the extension part 14a of the plate 14 and the brace material 13 may be joined together through a coupling member by bolts. It is preferable that an H-shaped sectional material or a square steel pipe is used as the brace material 13. This constitution eliminates a need for fillet welding between a metallic material for joining with the brace material 13 and the pole material 1 and reinforcement of the internal part of the pole material 1 and facilitates ensurance of strength through the execution of a simple work.

Friction welding method, device and tool therefor

Abstract: PROBLEM TO BE SOLVED: To provide a friction welding method, device and welding tool for a non-ferrous metal such as aluminum. SOLUTION: A probe 45 provided in a welding tool 19 is made to face the joining part of a work W1, W2 to be welded, frictional heat is produced between the probe 45 and the work by rotating the welding tool 19, and then, welding is performed by softening the joining part of the work with the frictional heat; in this case, in relatively moving the welding tool 19 against the work along the joining part, welding is performed with the welding tool 19 slightly inclined against the work so that the tip end 45T of the probe 45 precedes in the relative moving direction. In addition, the welding tool is equipped projectingly with the probe 45, which is for producing frictional heat through rotation relative to the work, on the tip end face of the tool body, and is formed with a recessed part surrounding the probe 45 in the tip end face of the tool body. COPYRIGHT: (C)1998,JPO

Cross-thickness vibration welding of polycarbonate, polyetherimide, poly(butylene terephthalate), and modified polyphenylene oxide

Abstract: In vibration welding of thermoplastics, frictional heat generated by vibrating two parts under pressure, along their common interface, is used to effect welds. In the normal, well-understood mode, the vibratory motion is along the weld seam, which is at right angles to the thickness direction for straight boundaries. But in many applications, such as in the welding of closed seams of box-like parts, this vibratory motion occurs in the part-thickness direction, so that a portion of the molten layer along the seam is exposed to the ambient air during each vibratory cycle. The resulting reduction in temperature can affect weld quality. The process phenomenology and the weld strengths of such cross-thickness vibration-welded butt joints are investigated for four neat resins. Weld amplitudes and weld pressures are shown to affect the strengths of 120-Hz welds differently. It is shown that strengths on the order of the strengths of the neat resins can be achieved in 250-Hz butt welds.

A method for butt welding thermoplastic pipe including automatic drag compensation

Abstract: A method for butt welding first and second thermoplastic pipes (12,14) to each other including the steps of locating the end portions of first and second pipes to be joined in clamps (20,22) that are moveable towards and away from each other by the application of hydraulic pressure, the pipe end portions being moveable against a facer for trimming the pipe ends at a first predetermined optimum hydraulic pressure, moveable against a heater for heating the pipe ends to a molten state at a second predetermined optimum hydraulic pressure and moveable towards each other while the ends are in a molten state to fuse the pipes at a third predetermined optimum hydraulic pressure, determining the hydraulic pressure required to move the pipe end portions towards each to determine a drag force hydraulic pressure, adding the drag force hydraulic pressure to each predetermined optimum hydraulic pressure to obtain first, second and third operating hydraulic pressures, and butt welding the pipes to each other using the first, second and third determined operating hydraulic pressures.

Method and equipment for welding vehicle body parts

Abstract: PROBLEM TO BE SOLVED: To produce the welding in which no positioning jig is required on a carrying device of a main part by welding a sub parts held by a handling robot to the main parts carried to the welding position in a set state by a welding robot. SOLUTION: When a main parts 3 is carried to the welding position by a carrying device 1, a handling robot 5 holes a sub parts 7 on a pallet 9, and positioned relative to the main parts 3 on the carrying device 1, and welded by a welding robot 11. Thus, a positioning jig of the main parts 3 on the carrying device 1 can be dispensed with, and the sub parts can be welded to the main parts 3 at a low cost. A holding part, an abutting part, and a hand part of the handling robot 5 and a pressing part, etc., of the welding robot 11 are adaptable to a work even when the work shape is slightly changed, and the manufacturing cost can be reduced. COPYRIGHT: (C)1998,JPO

Ultrahigh Molecular Weight Polyethylene

Abstract: This chapter focuses on the different types of welding used to bond ultrahigh molecular weight (UHMW) polyethylene polymer. Plug Welding is to be used in areas where it is undesirable or impossible to fasten Cadco UHMW sheeting by drilling holes through the existing substrate or support. Cadco UHMW can be welded with a low or high density polyethylene welding rod although the weld is not considered structural. It may nevertheless provide a good waterproof joint. Friction welding and butt welding are the only practical methods for joining Hostalen GUR by welding, because of its high melt viscosity. In butt welding, the cleaned joint faces are held under slight contact pressure against the heated tool at 200°C until on both sides a layer of about 4 mm deep has become plastic. In butt welding (heated tool welding), both surfaces of the Cadco UHMW are held against a Teflon-coated tool. This tool is heated electrically with a rheostat to control the tool's temperature.

Butt welding position detecting device

Abstract: PROBLEM TO BE SOLVED: To detect a butt welding position of the welding objects with high accuracy and reliability by choosing a lighting mode which casts a high edge image clarity when there is a step on the objects being placed in a butted shape. SOLUTION: When the welding object W1 is placed at higher than the welding object W2, and a light of the first protector 1a is switched on, it casts a shadow on the object W2. If these situations are photographed, by a camera 11 placed at right above, an edge image with a clear contrast can be obtained when there is a shadow, and only a light part forms an image when there is no shadow. The images of the object W1, W2 and a welding line, photographed under the lights illuminated by the first projector 1a and/or the second projector 1b, are to be image-processed by the image processor 12, and its output is supplied to the controller 10. The controller 10 decides a light switching method upon receipt of the report that the welding line is detected. The controller 10 repeats the welding line detection and the laser torch position adjustment against the detected welding line, and a detection of the top edge of the work.

Automobile seat frame and welding equipment for manufacturing the frame

Abstract: PROBLEM TO BE SOLVED: To eliminate the increasing tendency of the wire length of the wire crossing and connecting part in the outermost surrounding part where a seat pad is mounted for an automobile seat frame with a wire structure and the failure impairing the appearance and feel of the seat by a prominent ruggedness by improving the shape of a wire crossing and connecting part. SOLUTION: The crossing part of a first wire 2a with a second wires 2b, the part forming the outermost surrounding part in an automobile seat frame with a wire structure, is made into a T-shape so that a part of the side face of the linear part m in the first wire 2a is abutted on the end face of the second wire 2b, and then, butt welding is performed on such T-shaped abutting part with a welding current. By making the linear part m of the first wire 2a as the outermost surrounding part of the seat frame 1, the seat pad or seat cover is prevented from being damaged, feel is improved and the entire length of the wire is reduced.

Butt welding device for plank material

Abstract: PROBLEM TO BE SOLVED: To surely prevent a weld imperfection within the weld bead by detecting a butting position of plank materials, thickness of which are different, before the welding and calculating a discrepancy value between the welding point and the butting position and, then by driving a welding head in a direction to eliminate the discrepancy value. SOLUTION: When the laser welding head 1 starts to weld, while displacing its position in a shaft Y direction on a given welding line as instructed by a driving part 5, a butting position determining part 4 determines a pre-welding butting position C. On the other hand, a bead shape determining part 6 detects a center part of the welding bead 12 and determines if the welding is good or bad based on the shape of the bead 12. An amendment value calculation part 7 calculates a discrepancy value of the position C and the laser beam center line based on a difference between the position C determined by the position determine part 4 and the center part determined by the shape determination part 6. When the discrepancy value is within a given value, the driving head 1 is driven by the amendment value obtained on the basis of the discrepancy value to shift the center line position in a shaft X direction so that the center line matches the position C.

On-Line Estimation of Laser Weld Penetration

Abstract: High-power CO{sub 2} laser welding has been widely used in the industry because of its high productivity and excellent weld quality. In order to tap the potential of this process completely, it is important to have on-line weld quality inspection methods to improve the process productivity and reliability by achieving 100 percent weld inspection. Weld penetration is one of the most important factors critical to the quality of a laser weld. However, it is very difficult to directly measure the extent of penetration without sectioning the workpiece. In this paper a model-based penetration depth estimation technique suitable for the production environment is developed. The proposed model relates the temperature measured on the bottom surface of the workpiece, weld bead width, laser beam power and welding speed to penetration depth. The closed-loop depth estimator combines the model and a model-error compensator to compensate for the uncertainty in the measurement of the laser power and absorptivity. Other effects considered are the averaging due to the finite size of the sensor, delay based on the sensor location and the process and sensor dynamics. Several bead-on-plate and butt welds were made on low carbon steel plates to validate the static process models and themore » depth estimation scheme. Temperatures on the bottom surface of the workpiece during welding were measured using infrared thermocouples. The welds were sectioned longitudinally to obtain the penetration profile. The penetration profiles estimated by the depth estimator matched satisfactorily with the measured penetration profiles. The results validate the capability of the proposed depth estimator to estimate penetration depth and its ability to trace the dynamic changes in penetration depth.« less

Butt weld connection for pipes, esp. steam generator pipes - has a perpendicular pipe end to weld seam transition w.r.t.the pipe longitudinal axis

Abstract: Butt weld connection for two pipes, esp. steam generator pipes, made of different materials, esp. ferritic/martensitic and austenitic materials with different coeffts. of thermal expansion, comprises a weld (5) between the two pipe ends (3,4). The transition from the pipe ends to the weld seam is perpendicular to the pipe longitudinal axis for connections where the difference between the thermal expansion coeffts. of the pipe and weld material is large.

Method and apparatus for generating welding pressure in a roller seam welding machine

Abstract: In a roller seam welding machine, the upper welding roller is led through a welding-force adjustment device with two spring elements. One spring is already effective when the initial deflection of the welding roller occurs. The other spring comes into operation only when a certain deflection (D) is reached. A marked improvement in weld quality can be obtained in this way, particularly at the start of the weld seam.

Laser beam machine

Abstract: PROBLEM TO BE SOLVED: To obtain a highly reliable oscillating mechanism by oscillating the optical system with an actuator using a piezoelectric element and thereby enabling high frequency oscillation. SOLUTION: In machining by the irradiation of a laser beam 10 on the surface of an object 13 to be worked, the optical system is oscillated with an actuator 20 using a piezoelectric element. Accordingly, the fluctuating direction of the converging position of the laser beam varies depending on the oscillating direction of the optical system; therefore, for example, with the converging position varied in the direction crossing the machining line 14, the converging position traces a zigzag moving locus as the machining head moves along the machining line 14. As a result, in the case of butt welding, a gap or misalignment tolerance is expanded, relaxing machining accuracy required for the abutting end face. In addition, with the piezoelectric element used for the actuator 20, high frequency oscillation is made possible. Further, looseness or wear is less compared with a conventional mechanical mechanism; hence, there is high reliability for durability.

Method and installation for butt welding two sheet sections, and coil for use therewith

Abstract: Method for welding two sheet sections and device for carrying out said method. Welding is carried out in the form of butt welding by generating a high-frequency electromagnetic field with the aid of a coil. With this method the coil and the sheet sections are moved relative to one another during welding because the length of the coil is appreciably shorter than the length of the weld to be produced.

Retaining jig for welding pipe

Abstract: PROBLEM TO BE SOLVED: To carry out welding by a single person even in a narrow place that entails an inferior welding posture and to improve workability, in performing butt welding of a pipe, by adjusting an abutting space with the use of a U-shaped elastic connecting member. SOLUTION: The jig is constituted of two fixing parts 7a, 7b which butt two joining pipes 10A, B and which fasten each pipe; U-shaped connecting member 1 for elastically connecting both of these fixing parts 7a, 7b; and space adjusting member 9 which connects the fixing parts 7a, 7b on the open side of the U-shaped connecting member 1 and which is formed with bolts for adjusting the space. In connecting an existing pipe to a new pipe with this jig, one end of the existing pipe 10A is fastened and fixed by one fixing part 7a. Then, with one end of the new connecting pipe 10B fixed by the fixing part 7b in a state abutted on the pipe 10A, the space adjusting member 9 is rotated, deforming the curved part of the U-shaped elastic member. As a result, the welding end faces of the pipe 10A, B can be firmly abutted on each other.

Welding equipment for deformation preventing of tube and method thereof

Abstract: PROBLEM TO BE SOLVED: To automatically execute butt welding of a small diameter tube while preventing deformation. SOLUTION: A fixing base 12 is coaxially clamped to a tube 1 fixed/ supported by a clamp mechanism 11, the surrounding of a groove part 3 of butt welding is automatically welded one layer by one with a welding torch 20 supported to the fixing base 12 and mounted to a rotating base 13 rotatable around the tube 1. After each layer is welded, a deformation quantity and position of a tube 2 to be welded are detected by deformation/position detectors 19, 22 mounted to the rotating base 13. Based on these detected signals, a controller 24 starts welding or heating of next layer from the opposite position of max deformation point to cancel angular deformation and executes automatic welding of a small diameter tube while preventing deformation.

Joining method of welding wire

Abstract: PROBLEM TO BE SOLVED: To prevent bulging parts such as burrs and fins from generating in a joined part. SOLUTION: The tip end of a welding wire 10 with a diameter of 1.2mm is cut off nearly perpendicularly to the axis, and inserted into the hollow part of a mullite-made tubular piece 20 having an outer diameter of 2.5mm, inner diameter of 1.25mm and length of 5mm, so that the tip ends of the welding wires are abutted on each other nearly in the middle. The tip ends in the tubular piece are held firmly and conductively by means of a fastening device of a butt welding machine, pressurized, energized and joined. Upon completion of the welding, the hollow tubular part 20 inserted on the joined part is clamped with pliers, crushed and then removed.

Steel frame welding robot systems and their application at the construction site

Abstract: Two welding robot systems have been developed to rationalize steel–frame construction. Both systems consist essentially of two portable cartesian–coordinate welding robots mounted on a carriage together with their ancillaries. After the robots are mounted on a beam or column by an operator, they measure the groove shape of the joint seam, determine the optimal welding conditions, and carry out welding from the first to the last layer without operator intervention. An important feature of the column–beam welding system is the curved torch, with which the robot can continuously weld the bottom flange of a beam through a scallop. Since the pantograph of the carriage can extend three floors, up to 12 joints can be welded from one carriage position. In welding column–column joints, two robots traveling on a circumferential rail installed near the seam of a rectangular hollow section weld the joint in combination. The robots can continuously weld a seam containing corners without weld defects even in joints with a misaligned groove. Each system has been applied to actual construction sites and has proved effective in stabilizing the quality of welds and in raising welding productivity.