Showing papers on "Butt welding published in 1992"

Multiple operator welding apparatus

Abstract: A multiple operator welding apparatus is disclosed which is particularly well suited for use in stick arc welding, GTAW, FCAW, ACAC, and GMAW arc welding processes. One or more welding modules are selectively mounted in a main power frame and connected to the power source by a knife blade connector which permits removal and replacement of one or more welding modules while the power source is in use. The knife blade connector also permits one or more welding modules to be removed from the main power frame and used at a remote location. The welding module for use with the multiple operator welding apparatus incorporates an inductor which permits use of a reduced incoming module voltage while producing a satisfactory weld. The reduced incoming module voltage results in significant energy savings.

High production laser welding assembly and method

Abstract: A method for butt welding metallic sheets along a relatively long common seam line by providing a plurality of laser welding devices aligned above the common seam line, and effectively spaced from one another along a longitudinal axis. In a preferred embodiment, each welding device is independently adjustable in a direction parallel to a transverse axis which is perpendicular to the longitudinal axis. The metallic sheets are aligned on the upper surface in abutting relationship along the seam line and clamped for welding. Each laser welds only a portion of the sheets along the seam line, and the length of the relative movement between the welding devices and the sheets is greater than the effective spacing distance between welding devices to insure that a continuous weld bead is provided along the common seam line.

Welding residual stress and distortion

Abstract: A characteristic of application-oriented analysis of welding residual stress and distortion is the mainly decoupled representation of the thermal, mechanical and microstructural processes (illustrated by the line arrows in Fig. 3). The basis of stress and distortion analysis is the temperature field during welding, determined numerically or by measurement, as well as the microstructural changes caused by the temperature field (presented in Chapter 2). Coupling effects are only occasionally taken into account.

Friction welding and welds made by friction

Abstract: Friction welding is preformed by linear or non-rotating orbital motion in which both parts to be joined by friction welding are moved in identical paths, out of phase to produce friction until welding temperature is attained, and then in phase, with the parts registered in alignment, during the bonding phase. Because the registered, in phase control of the mechanism is attainable with great certainty and rapidity, friction welding with a far higher precision and accuracy of alignment is attained. The high precision and accuracy of the technique permits application of friction welding to fabrication of parts, such as turbine engines, not usually made by such techniques. A preferred apparatus for practice of the invention involves an opposed pair of orbital tables (110 and 120), on which parts to be joined are mounted and fixed in place by mounts 113 and 123). The parts are aligned and registered and drives (111 and 121) then cause the parts to orbit while they are pressed together by pressure means (14), until friction heats the joint surfaces to welding temperatures.

Arrangement for butt-welding plastic material components

Abstract: An arrangement for butt-welding tubular plastic components includes two chucking devices for holding the components in coaxial positions relative to each other and a heating device for heating the ends of the components without contact. The heating device includes a heating element which can be swung between the two chucking devices. The heating element heats the ends of the components without contact by heat rays. The heating element includes a metal plate which is coated with a ceramic coating and which is electrically heatable by heating cartridges.

Apparatus for carrying out mig welding on three-dimensional curved surface, and milling apparatus for automatically forming welding grooves

Abstract: An automatic welding apparatus and an automatic milling apparatus for machining welding grooves in order to weld a three-dimensional surface such as a ball tank or the like are disclosed A welding wire spool is accommodated within a case and a cover to prevent the welding wire from being oxidized and from being contaminated with foreign materials The automatic milling apparatus is installed to form welding grooves on the both sides of the objects to be welded, in the case where a welding is performed on a three-dimensional curved surface A guide roller having a handle is installed to control the machining depth of the grooves, and an idling type nylon guide roller is installed in closed contact with the shaft of a cutter, thereby adjusting the distance between the rail and the groove, and adjusting the deviations of the depth of the grooves, which are caused by the machining inaccuracies due to the deviations of the three-dimensional curvature

Analysis of the deformation of polypropylene hot‐tool butt welds

Abstract: Thin microtomed samples from hot-tool butt welds of polypropylene pipes are subjected to uniaxial tensile stress using a specially built instrumented microtesting machine. The deformation of the interface between the weld and the bulk polymer is measured by an optical method. An analysis of these measurements is carried out using the finite element method, and contours of the effective stress are obtained. There is a steep stress gradient at the junction of the weld flash and the bulk polymer, although the stress concentration factor is relatively low. The stress is essentially constant in the bulk polymer apart from the region near the weld zone. Tests on samples without the weld flash show that the maximum stress occurs within the weld zone. This is consistent with long-term tests on larger samples, where the fracture is found to initiate within the weld. The method of analysis enables the stress-strain response of the weld material to be determined.

Mold including a low thermal inertia heater and method of using same

Abstract: A mold, having a mold cavity commensurate with the shaping, forming or welding to be made, includes an RF energized heater in close proximity to the mold cavity for heating plastic tubing placed within the mold cavity to a temperature sufficient to shape, form or weld the plastic tubing. An RF generator, electrically connected to the RF energized heater, monitors the power applied as a function of the temperature of the heater to heat the plastic tubing to a precise temperature. The mold is of thin wall construction with minimal thermal inertia to expedite both heating and cooling. Various configurations of the mold may be made to form tip shaping, forming or welding, butt welds, annular welds and the like to weld single thermoformable elements or join multiple thermoformable elements.

Method and apparatus for making a printing screen

Abstract: A method and apparatus for making a true butt-welded cylindrical printing screen for a rotary screen printing press, wherein the screen material is rigidized woven metal screen. The method of making the cylindrical screen of the invention includes the steps of cutting a rectangular piece of rigidized woven metal screen material of a size to form a screen of a predetermined size, forming the piece into a cylindrical shape so that two edges are abutting each other to form a butt seam such that sufficient metal will be present to provide a proper weld, mounting the screen on a support bar so that the abutting edges line up with a stationary electrode carried by the support bar, where the electrode includes a tip of narrow width in the range of 0.010 to 0.040 inches, and running an upper electrode along the other side of the butt seam to resistance weld the two edges of the screen material together and form a butt weld. The apparatus includes a support bar for holding the stationary electrode, means for mounting and holding the screen material edges together on the support bar in alignment with a thin elongated electrode carried by the support bar, and means for driving an upper electrode along the butt seam to effect the welding of the edges together.

Joined clad plate and its manufacture

Abstract: PURPOSE:To obtain the joined clad plate where functions and characteristics which base plate material and material to be clad have respectively are not marred by allowing the same materials to abut on each other, welding only high melting point side material and further, welding low melting point side material. CONSTITUTION:A butt part 8 of the high melting point material 4 is irradiated with a laser beam and welded up to the depth (d). At this time, since the beam is narrowed down finely and the butt part 8 can be welded when laser beam welding is used, a value of (a) of a bead part 6 becomes smaller desirably. The butt part 8 of the low melting point material 5 is then welded up to the depth (d') by laser beam welding. A value of (a') of a bead part 7 also becomes smaller in the same way in this case. Consequently, cladding is attained in the bead parts 6 and 7 and the whole joined clad plate 1 after welding including the bead parts 6 and 7 holds various properties which the clad plate has before welding.

Ultrasonic device for welding and cutting natural, synthetic or mixed fabrics without fraying

Abstract: Ultrasonic device for welding and cutting natural, synthetic or mixed fabrics, comprising an ultrasound converter which is operatively coupled to a sonotrode (3) which is constituted by a tool, one end of which cooperates with a working surface and has a welding region (43) and a cutter (44) which is connected to the welding region downstream with respect to the direction of advancement of the material (11) to be welded. Means are provided for the orientatable support of the tool so that the cutter (44) has one end in contact with the working surface (4) and the welding region (43) is raised with respect to the working surface, so as to provide a guide for the insertion of the material (11) to be welded beneath said region and allow the welding of the material along a band (N) whose width corresponds to the width of the welding region and the cutting of the band so as to produce two adjacent welded edges.

Development of an intelligent system for cooling rate and fill control in GMAW

Abstract: A control strategy for gas metal arc welding (GMAW) is developed in which the welding system detects certain existing conditions and adjusts the process in accordance to pre-specified rules. This strategy is used to control the reinforcement and weld bead centerline cooling rate during welding. Relationships between heat and mass transfer rates to the base metal and the required electrode speed and welding speed for specific open circuit voltages are taught to a artificial neural network. Control rules are programmed into a fuzzy logic system. TRADITOINAL CONTROL OF THE GMAW PROCESS is based on the use of explicit welding procedures detailing allowable parameter ranges on a pass by pass basis for a given weld. The present work is an exploration of a completely different approach to welding control. In this work the objectives are to produce welds having desired weld bead reinforcements while maintaining the weld bead centerline cooling rate at preselected values. The need for this specific control is related to fabrication requirements for specific types of pressure vessels. The control strategy involves measuring weld joint transverse cross-sectional area ahead of the welding torch and the weld bead centerline cooling rate behind the weld pool, both by means ofmore » video (2), calculating the required process parameters necessary to obtain the needed heat and mass transfer rates (in appropriate dimensions) by means of an artificial neural network, and controlling the heat transfer rate by means of a fuzzy logic controller (3). The result is a welding machine that senses the welding conditions and responds to those conditions on the basis of logical rules, as opposed to producing a weld based on a specific procedure.« less

Method and device for manufacturing welded tube

Abstract: PURPOSE: To reduce an uneven metal between a weld zone and a base metal part, which is generated at the time of contracting the diameter by cold working by a reducer with respect to a welded tube. CONSTITUTION: While carrying a strip S in its longitudinal axial direction, it is formed to an open pipe OP in which both side edge parts E, E in the width direction are opposed to each other by a forming roll group of a breakdown roll 3, a cluster roll 4 and a fin pass roll 5, and both side edge parts E, E of the open pipe OP are set to a heated and melted state by a welding machine 7. Subsequently, both side edge parts E, E are subjected to butt welding by a squeeze roll 6, and thereafter, metal increase forming is executed to a welded tube P by a metal increase forming machine 8, and thereafter, a weld zone is cooled by a cooling device 9, and the diameter reduction is performed, while imparting a stretch by a reducer 10, or without imparting the stretch. COPYRIGHT: (C)1993,JPO&Japio

Butt welding method for thick plates

Abstract: PURPOSE:To provide the butt welding method of the thick plates where there is no work before and after welding and automation is made possible, a welded joint with little thermal effect is obtained and a large-sized restraining device to restrain thermal strain is obviated. CONSTITUTION:In butt-welding base metals 1 of the thick plates, a groove shape is formed into a Y-shaped groove 2, a straight part of the Y-shaped groove 2 is welded by a laser irradiation beam 4 from an overhead laser head 3 and afterward, a V-shaped part of the Y-shaped groove 2 is flat-welded by wires 6a and 6b of plural gas shielded arc welding torches 5a and 5b.

Assembly process by welding of two solid copper pieces and assembly performed using such a process

Abstract: Two solid copper pieces are assembled by welding without filler metal. The pieces both have a projection which are placed facing and in contact with one another, before the pieces to be assembled are placed on the welding press. Welding is performed by passing a very high intensity current for a short period of about one tenth of a second under very high pressure. The welding operation prevents any annealing of the copper.

Welding head for measuring welding parameters and the application thereof to automatic welding

Abstract: A welding head and process for measuring welding parameters, and the application thereof to automatic welding, which make it possible to measure welding parameters by use of a mechanism for viewing the welding scene. This welding scene is illuminated by the arc and the electrode and includes light spots projected by a laser source through a nozzle. The scene thus illuminated is transformed into images by the picture-taking mechanism which is able to determine the position of the spots and to determine the height of the welding head above the welding scene, by a method of triangulation. The picture-taking angle of the picture-taking mechanism can be modified to make it possible to determine several welding parameters. The welding head can be incorporated into an automatic welding system and can be applied in all high-technology industrial fields requiring automatic welding, such as the space, nuclear, or aeronautics fields.

Method and system for computer-assisted welding, based on the welding area vision

Abstract: The invention relates to a method and a system for computer-aided welding. This automatic welding method, processing images taken during a welding activity, is based on learning from welding cases already treated. It comprises operations for preestablishing relationships between the welding parameters; for installing, in the form of equipment or software, these relationships in a welding system and then the execution by this system; for taking pictures of a welding area during welding; for analysing each of these pictures in order to measure some of the welding parameters; for evaluating, from these relationships, values for correcting the welding parameters; and for intervening, as a function of this evaluation, with the welding in progress. This method is implemented by a system comprising a welding head capable of taking the pictures, and a control and processing unit capable of applying the said method. The invention finds numerous applications in all high-tech industrial fields, such as the aeronautical and nuclear fields.

Plate butt welding - uses powder material inserted into joint to be melted by resistance heat from rolling electrodes

Abstract: The rolled seam to join plates together, by resistance welding in a butt joint, is prepared by inserting a metallic powder (7) into the joint zone (a) as an added material. The powder covers the joint and has a chemical composition and grain size compatible with the welding conditions. During welding, the resistance heat generated by the electrodes (4,5) melts the powder to fill the joint (a) completely, and give a bond between the two plates (1,2). ADVANTAGE - The operation gives a total bond between the two plates and the material in the joint between them, so that welding faults are prevented to avoid later failure.

System and device for manufacturing rib stock

Abstract: PURPOSE:To improve the welding quality by detecting a butt state of both end faces from displacement of the flat surface of a butt end part of a cylindrical winding rim stock. CONSTITUTION:At the time of manufacturing a wheel rim for an automobile, with respect to a rim stock W wound cylindrically by coiling a plate cut to a fixed size, its butt end parts are formed in flat parts A, B by press working before executing butt welding. Subsequently, whether a butt state of its flat parts A, B is satisfactory or not is confirmed automatically by sensors 18, 19, and thereafter, welding is performed. In such a way, a stable welding quality can be secured, and also, a damage accident of the device can be prevented in advance.

Resistance welding machine, particularly for resistance flash welding of rails

Abstract: The rail welding machine, in particular for the butt welding of railroad rails (7a), has electrodes (11a, 11b) to be applied over a large area to the rails (7a), which are articulated on their supports (41a, 41b). The structural unit which can be moved to feed one of the rails (7a) is mounted in an oscillating manner in the feed direction. Due to the mobility of the electrodes (11a, 11b), they can be applied without problems over a large area to the surface of the workpiece to be welded, here the railroad tracks (7a). This results in an almost uniform current flow over the contact surface, which can prevent overheated contact points. Due to the smooth storage, d. H. The oscillating suspension of the assembly in the welding feed direction enables extremely precise feed of the one rail end and an exactly metered feed force during the welding process. Through the precise control of the welding current, the feed force and the feed path, an excellent quality of the butt welding can be achieved.

Investigation of keyhole and melt pool dynamics during laser butt welding of sheet steel using a high speed camera

Abstract: An investigation was undertaken using a high power carbon dioxide laser into the butt welding of mild sheet steel, addressing the problem of variable weld quality as a result of keyhole and thus melt pool stability. Using a high speed video camera the temporal behaviour of the keyhole and melt pool are monitored. Experimentation is centred around the effect of various interface geometries; guillotine, milled and angled edges on the weld quality. The range of processing conditions with respect to speed/power used varies from 140 to 260mm/s AT 3.5KW. When the processing speed approaches a critical level, related to the type of interface profile, the onset of high speed weld defects occurs particularly the humping phenomenon and weld porosity. From the pictures obtained using the video equipment the extent to which and at what speed this occurs is largely dependent on the capillary flow conditions within the melt pool. The onset of this defect can be prolonged by carrying out the welding operation on samples with guillotined edges angled perpendicular to the direction of welding with the laser beam slightly offset from the welding line. This process improvement offers increased penetration and more importantly increased reliability for the welding operation at a processing speed of 15.5m/min. with the added advantage of no special edge preparation.An investigation was undertaken using a high power carbon dioxide laser into the butt welding of mild sheet steel, addressing the problem of variable weld quality as a result of keyhole and thus melt pool stability. Using a high speed video camera the temporal behaviour of the keyhole and melt pool are monitored. Experimentation is centred around the effect of various interface geometries; guillotine, milled and angled edges on the weld quality. The range of processing conditions with respect to speed/power used varies from 140 to 260mm/s AT 3.5KW. When the processing speed approaches a critical level, related to the type of interface profile, the onset of high speed weld defects occurs particularly the humping phenomenon and weld porosity. From the pictures obtained using the video equipment the extent to which and at what speed this occurs is largely dependent on the capillary flow conditions within the melt pool. The onset of this defect can be prolonged by carrying out the welding operation on samples...

Development of Low Frequency Pulsed MIG Welding Process for Al and its alloy. Study on Low Frequency Pulsed MIG Welding Process. (Report 1).

Abstract: The low frequency pulsed MIG welding process of new current waveform control to switch over unit pulse conditions (pulse current, pulse duration) in the fixed cycle was developed and its effect were investigated for aluminium and its alloy.By using this new welding process, the bead appearance having clear ripple pattern, such as TIG welding bead can be obtained and the gap tolerance of lap and butt welding joint can be expanded.

Laser beam strip butt welding process - involves laser trimming of clamped strip ends before welding

Abstract: In the laser beam butt welding of strips the strip end edges are cut off by a laser beam before welding. The roughly cut strip ends are trimmed at least once with the laser in the laser cutting and welding machine while the strip ends are clamped by jaws which apply a pressing force of at least 30t. per m. strip width. Each strip end is trimmed with a circularly polarised laser beam with a supersonic nitrogen flow into the cutting gap so that the cut edges exhibit (over two-thirds of the cut depth) a roughness (Rz) of max. 60 microns prior to welding, the free strip length, projecting beyond the clamping jaws after the last laser cut, being max. 50mm. Welding is carried out while the strps are still clamped. Appts. for carrying and the process is also claimed. USE/ADVANTAG - The process is used esp. in rolling mills for butt welding hot and/or cold rolled strip ends. It allows faultless welding even of strips of alloy steel contg. 12% Cr or more and of more than 3 (pref. 4-10)mm, thickness, without user of weld additive.

Welding with a 3kW Nd:YAG laser

Abstract: An Nd:YAG laser facility with a maximum average output power of 3kW has been established with the aim of determining the material processing benefits offered at power levels significantly above those available from current commercial Nd:YAG lasers.Welding trials have been conducted in a wide variety of materials representative of those used in the automotive, aerospace and power generation industries.Encouraging results have been obtained in overlap and spot welding of zinc coated automotive steels, overlap and butt welding of aluminium alloys and welding of aerospace and structural alloys in thicknesses up to 9.6mm.An Nd:YAG laser facility with a maximum average output power of 3kW has been established with the aim of determining the material processing benefits offered at power levels significantly above those available from current commercial Nd:YAG lasers.Welding trials have been conducted in a wide variety of materials representative of those used in the automotive, aerospace and power generation industries.Encouraging results have been obtained in overlap and spot welding of zinc coated automotive steels, overlap and butt welding of aluminium alloys and welding of aerospace and structural alloys in thicknesses up to 9.6mm.

Butt welding device of plastic part

Abstract: PURPOSE: To provide a machine for butt-welding of a plastic component and particularly a tubular product and a pipe CONSTITUTION: The butt-welding machine for a plastic component comprises a heater 7 for heating an end of a component without contact with two chucking units 4, 5 for holding the component axially The heater 7 has a heating element 12 oscillating between the units 4 and 5 The element 12 heats the end of the component without contact by a heat ray The element 12 is covered with a ceramic coating layer 14, and has a metal plate 13 electrically heatable by a heating cartridge 15

Rotary forged curved side flange for five piece rims

Abstract: A continuous forged annular flange (10) is provided for use in a wheel assembly (12) to support the side wall of a tire (14). The continuous forged flange eliminates butt welds used in prior designs which formed points for stress concentration. Further, the flange need not be cold worked and therefore has no induced stresses as present in prior designs which can lead to fatigue failure. In addition, the flange can be of a metal different than other parts of the wheel assembly to reduce electrolytic corrosion.