GB2174325A - Bilateral rib welding machine - Google Patents

Abstract

The machine for welding both side edges of a rib (39) to a web (38) comprises a guide track (1), a welding head (17, 22, 24) movable along the guide track (1) and operable to carry out the simultaneous welding. An arrangement (10, 11) mounts the guide track (1) to support the welding head over the web (38). A pair of guides (24) are carried by the welding head and each engageable along a respective one of the side edges of the rib (39), with a pair of welding torches on the welding head arranged to follow the respective guides. An inverted channel-shaped frame (17) mounts the welding head, and a slider (13) on which the frame is mounted moves along the guide track (1). Each guide (24) and welding torch is rigidly mounted at the lower end of an elbow (22) pivotally mounted at (21) at its upper end on a respective limb (20) of the frame (17), whereby the guide (24) and torch can be moved jointly between operative and inoperative welding positions permitting lateral head movement relative to the rib (38), to enable welding of a further rib on the web (38), carried out by guide rollers (11) which run along the upper edges of flanges (40) of the composite beam structure. Lateral adjustment means (5, 6) and vertical adjustment means (8, 9) connect the guide track (1) to the support arrangement (10) and permit automatic relative lateral and vertical guide track (1) adjustment during head movement. <IMAGE>

Description

SPECIFICATION Bilateral rib welding machine This invention relates to a bilateral rib welding machineforthe simultaneous welding of both side edges of a rib to a web so as to form a composite welded beam structure.

Examples of composite welded beam structures which can beformed by a welding machine according to the invention include compound beams with L, inverted T and I type profiles.

Abilateral rib welding machineforthe simultaneous welding of compound rib beams is known, which comprises an inverted channel shaped frame and driving wheels placed on bearings at both ends of the frame. Two consoles are rigidlyfastened perpendicular to the front of the frame at both ends.

A leading arm on bearings is mounted on each console, parallel to the channel frame. Each leading arm is composed oftwo parts inclined ata predetermined angle to each other. A guide or copying roller is rigidly fastened to the leading arm and is mounted at the lower end thereof. There extend laterally from the leading arms parallel members on which welding torches are fastened. A control panel and two welding wire feeding devices are mounted on the inverted channel shaped frame, and two manually controlled handles are based on the sides of the leading arm to permit of manual manipulation of the welding torches.

The disadvantages of the known welding machine arethatself-centering cannot be achieved during welding, and hence manual correction is required.

Moreover, it cannot be used for welding or perpendicularly extending ribs on a web, since the driving unitandthe copying unit lie in one andthe same plane, thus leaving behind an unwelded part on the rib. Further,the machine cannot be moved laterallyfromoneribtoanotherbyasingle operative, and a lifting device is required. Also, it cannot be used for welding of ribs which are spaced apart by a distance less than 400 mm, and it calls fora constant control overthewelding bows which leads to the fact that the welder must inevitably be placed in the region of greatest harmful welding vapours.

Finally, the known machine cannot move evenly at a greater pitch of the rib, orwith a wave-like web, because of danger of slipping of the driving wheels.

The present invention has therefore been developed primarily, though not exclusively, to provide a bilateral rib welding machinewhich is an improvement overthe known machine, and which can achieve automatic up and down and lateral selfcentering of the welding torches during a welding operation, while at the same time not changing the initially set relative position of the welding torches. In addition, the movement of the welding torches should not be adversely influenced by the welding surface, and the formation of welding seams can be achieved in limited spaces on both sides ofthe rib.

Also, the machine should be capable of being moved more readily laterally from one rib which has been welded to another rib which isto be welded to the web.

According to the invention there is provided a bilateral rib welding machine for the simultaneous welding of both side edges of a ribto aweb so asto form a composite welded beam structure, the machine comprising: a guide track; a welding head which is movable along the guide track and which is operable to carry out simultaneous welding along both side edges of the rib in orderto weldthe ribto the web; a support arrangement on which said guide track is mountedandarrangedtosupportthewelding head overthe web; a pair of guides carried by the welding head and each engageable along a respective one of the side edges ofthe rib;; a pair ofwelding torches carried by the welding head and each arranged to follow a respective one of the guides, during movement of the welding head along the rib, and to carry out welding along the respective side edge; an inverted channel-shaped frame on which said welding head is mounted; a slider on which said frame is mounted and which is mounted for movement along said guide track; means mounting each guide and respective welding torch on the welding head for joint movement between an operative position along a respective side of the rib and an inoperative position permitting lateral movement of the welding head relative to the rib; lateral adjustment means connecting the guide trackto the support arrangement and operable to permit of automatic relative lateral adjustment ofthe guide track as the guides of the welding head follow the line ofthe rib;; and further adjustment means connecting the guide trackto the support arrangement and operable to permit of automatic relative up and down movement of the guide track as the guides of the welding head engage the web they follow the line ofthe rib.

A bilateral rib welding machine according to the invention may be constructed so as to provide a precise and reliable self-centering of the welding torches during welding, both in the horizontal and the vertical plane, and which permits welding seams of high qualityto be obtained. The machine can work satisfactorily in a limited working area, so that welding of a rib to a web can be carried out completely, without being limited by the presence of flanges on the ends ofthe web. The machine need not be heavy, and can bye moved laterally from one rib to another, with greater speed than is presently possible with known machines. It can also weld ribs spaced less than 300 or 400 mm apart, and is not adversely influenced by the pitch orthe smoothness of the web and the ribs of the composite beam undergoing welding.

One embodiment of bilateral rib welding machine according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a side view of the welding machine during a welding traverse along the length of a rib which isto be welded to the web of a double flanged I-beam lying on its side; Figure 2 is a sectional view taken on the line B-B in Figure 1; and Figure 3 is a diagram of the forces acting on a welding head of the machine in use, and illustrating the vertical and horizontal centering forces.

As will become apparent from the subsequent detailed description of a preferred embodiment of the invention, there is disclosed herein a bilateral rib welding machine for the simultaneous welding of both side edges of a rib 39 to a web 38 so as to form a composite welded beam structure. The machine comprises a guide track 1, a welding head 31, 17, 22, 24 and 26 which is movable along the guide track 1 and which is operable to carry out simultaneous welding along both side edges of the rib 39 in order to weld the rib to the web, a support arrangement 10, 11 on which the guide track 1 is mounted and arranged to support the welding head over the web 38, a pair of guides 24 carried by the welding head and each engageable along a respective one of the side edges of the rib 39, a pair of welding torches 26 carried by the welding head and each arranged to follow a respective one of the guides so as to carry out welding along the respective side edge of the rib, an inverted channel-shaped frame 17 on which the welding head is mounted, and a slider 13 on which the shaped frame is mounted and which is mounted for movement along the guide track 1.

Each guide 24 and respective welding torch 26 is rigidly mounted at the lower end of an elbow 22 which is pivotally mounted at 21 at its upper end on a lower end of a respective limb 20 of the shaped frame 17, whereby the guide 24 and torch 26 can be moved jointly between an operative welding position and an inoperative position permitting lateral movement of the welding head relative to the rib 38, to a position suitable for carrying out welding of a further rib on the web 38. This lateral movement is carried out by guide rollers 11 carried by support beams 10 which run along the upper edges of flanges 40 of the composite beam structure. Lateral adjustment means 5, 6 connect the guide track 1 to the support arrangement 10 and are operable to permit of automatic relative lateral adjustment of the guide track 1 as the guides 24 of the welding head follow the line of the rib 39.Vertical adjustment means 8, 9 connect the guide track 1 to the support arrangement 10 and are operable to permit of automatic up and down movement of the guide track 1 as the guides 24 of the welding head engage the web 38 as they follow the line of the rib 39.

Referring now to the drawings, the bilateral rib welding machine comprises a guide track in the form of a rack 1,which is rigidly mounted on a support beam 3 by means of bolts 2. At both ends of the beam 3, from below, are mounted two devices 5 which form part of lateral adjustment means which permit of automatic relative lateral adjustment of the rack 1 as the welding head of the machine carries out a welding traverse. On each device 5 there are rigidly welded pivots 6 with threaded ends.

The pivots 6 are mounted by means of bearings on two devices 7 which form part of vertical adjustment means for regulating the up and down position of the rack 1 relative to the welding plane. The vertical adjustment means 7 comprises two arms 8 mounted by means of two pivots at their upper ends to a beam 9 and by two pivots at their lower ends to a support arrangement beam 10. Further, onto the beam 9, the vertical pivots 6 are mounted on bearings.

Support beams 10 are mounted atthe front and rear of the welding machine, to form a support arrangement for the welding head, and carry on their lower edges guide rollers 11 which can run along the upper edges of the flanges 40 of a composite I-beam structure which is lying on its side, as shown in Figure 1. The guide rollers 11 are rotatably mounted on the beams 10 by journals 12.

The welding machine includes a welding head which is provided by a pair of guides in the form of copy rollers 24 which are mounted at the lower ends of elbows 22, and respective welding torches 26 which are fixedly mounted relative to the guides by being mounted on parallel extending support members 25 secured to the lower ends ofthe elbows 22. The welding head is mounted for movement along the rack 1 and is operable to carry out simultaneous welding along both side edges of a rib 39 which is to be welded to a web 38 of a composite beam structure. The mounting of the welding head so that it can be supported for movement over the web 38 is provided by support arrangement 10 and 11, and also by means, described below, which mount the welding head for movement along the beam 3 and rack 1.

This intermediate support means includes a slider 13 which is movable along the guide rack 1 by means of guide rollers 14 which are rotatable about vertical axes and which engage the side faces of the rack 1, which are formed as slotted channels.

To the slider 13, there is attached a pivotally mounted elongate support arm 16, which carries the welding head proper. The support arm 15 is pivotally mounted at one end (the left hand end in Figure 1) on the slider 13 by means of horizontal pivots 16, and an adjustable cam mechanism 32,33 is operative between the underside of the support 16 and the slider 13 in order to adjust the relative inclination (a) between the support 16 and the slider 13. The preferred angle a = 5 , though this can be adjusted within the range 5 to 15 , by suitable adjustment of the cam machanism 32,33.

An inverted channel shaped support frame 17 is secured by welding to the forward end of the support 16, the frame 17 being symmetrical about the axis of the support 16 and lying in this plane. As will be seen particularly from Figure 2, the downwardly extending limbs 19 of the channel frame 17 have mounted thereon the upper ends of the elbows 22 of the welding head, by means of horizontal pivots 21.Fixing units 20 are provided to secure the elbows 22 in upwardly pivoted inoperative positions (pivoted upwardly away from the operative position shown in Figure 2), to permit of ready lateral movement of the entire welding head relative to the rib 39, to position the welding head in a suitable position for a longitudinal welding traverse along a further rib which is to be welded to the composite beam structure This further rib (not shown) may be spaced as closely as 300 to 400 mm away from the shown rib, and yet still be satisfactorily welded by the machine.

The downwardly projecting limbs of the inverted channel shaped frame 17 are formed by lugs 19 which are bolted by bolts 18 to the underside ofthe horizontal top part of the frame 17.

The elbows 22 are composed oftwo rigidly interconnected parts, connected at an angle of about 1350 to each other and, as indicated above, copy or guide rollers 24 are pivotally mounted on inclined pivots 23 at the lower ends of the elbows 22. As also mentioned, transversely of the elbows 22 there a re rigidly fastened the parallel support members 25, which permit of horizontal and vertical deviation of the welding torches 26 during a traverse ofthe welding head along the surface of the web 38 and adjacent to either side of the rib 39.

On the upper part ofthe elongate support 16, laterally spaced from the frame 17, there is secured via a support bracket 27 a pair of supply drums 29 rotatable on pivot28andadaptedtosupplywelding wire to the welding torches 26. Forwardly spaced from the support bracket 27 there iswire-feeding device 30 also mounted on the upper surface ofthe support 16. On the upper part of the channel frame 17 there is a control panel 31.

In orderto draw the welding head along the line of the rib 39, a tractor unit 34 is rigidly connected to the front part of the slider 13, and engages via rollers 35 lying in slotted channels ofthe rack 1. Two end switches 36 are provided for engagement bythe device 7, the device lying transversely to the elbows 22. A remote control unit 37 is connected to the control panel 31.

The operation of the bilateral rib welding machine will now be described.

Before placing the machine onto the beam to be welded, depending on its overall dimensions, a preliminary adjustmentforvertical and horizontal position of rack 1 is done, which is achieved by the devices for angular deviation 5 and the devices for vertical adjustment. This adjustment is necessary, so thatflanges 40 ofthe beam structure can be held by the flanges of the rollers 11. The distance from the web 38 of the welded beam to the lower end of beam 3 is determined so that supportarm 16 is at an angle a = 5"--1 5", according to the plane ofthe slider 13.

When this is achieved, the copying rollers 24 completely touch the web 38 and the rib 39 ofthe welded beam. The machine is placed on the welded beam by a crane or other lifting device. The moving ofthe machine along the flanges 40 is done by means of the rollers 11, while beforehand the lifting cam mechanism 32 is rotated fully to the right. Afterwards the leading arms (elbows) 22 are pivoted upwardly about pivots 21 up to a horizontal position ofthe copying rollers 24 and are made immobile by fixing units 20.When the gear strip (rack) 1 reaches a position parallel to the welded rib 39, the fixing units 20 are switched-off and leading arms 22 go downwards because of their own weight to reach rib 39. Afterthatslider 13 together with tractor 34, by means of rollers 14and 35, is manually moved along flange 40 of the welded beam until welding burners (torches) 26 reach the web 38. Cam mechanism 33 is evenly rotated to the right and the leading arms 22 are fed to the web 38 by means ofthe copying rollers 24.As a result of the tight connection between support arm 16 and the leading arms 22 underthe action oftheweightofthewire4eeding device 30, control board 31, supply drums 29 and of the support arm 16, the vertical pivots 6 are activated together with horizontal pivots 21 and 15 and the rollers 11, whereby an initial centering of the machine is done according to rib 39 and web 38 of the beam. After that the pitch ofthewelding burners is determined by means of parallel supports 25. From the control board 31 is switched the operations of the tractor 34, which starts moving along gear strip 1 in the direction of welding. Afterthatthe wire-feeding device 30 is activated and the welding begins.

While slider 13 is moving as shown in Fig. 3 as a result oftheforces acting upon the machine, a selfcentering of the welding burners 26 is achieved. The towing force F and force G act upon the machine.

Force F results from the movement of tractor 34 along gear strip 1,which acts upon slider 13. Force G results from the weight of arm 16,frame 17, leading arms 22 and all the mechanisms mounted on support arm 16. When the machine moves in the direction of welding, under the action offorces F and G and because of the inclination of support arm 16 at angle a = 515% 5", as well as oftheangle between elbows 22 and the welded rib 39, which is 45% the resulting centering force C is obtained. During welding, the value of the resulting centering force C depends on the pitch of support arm 16 and on the value offorce G.

When the position is not precise, there is a displacement and at the same time crossing of gear strip 1 with rib 39 during welding, and underthe action of force G are additionally activated pivots 6, 21 and 15 and rollers 11. As a result the machine is self-centered when at work, and maintains unchanged the pitch (inclination to the horizontal) of the welding burners 26. When reaching the end of a welding seam, the terminal switches 36 are activated thus stopping tractor 35 first, then thewire-feeding device 30. Via the remote distance control 37 tractor 34 is reversed in a direction opposite to the direction of welding, until rollers 24 are separated at a distance from flange 40. Cam mechanism 32 is rotated to the rightfully, leading arms 22 rotate about pivots 21 until fixing units 20 auto#matically stop them, and the machine is ready to be moved along flanges 40 to the next rib (not shown).

Claims (1)

1. A bilateral rib welding machineforthe simultaneous welding of both side edges of a rib to a web so as to form a composite welded beam structure,the machine comprising: a guide track; a welding head which is movable along the guide track and which is operable to carry out simultaneous welding along both side edges of the rib in orderto weld the rib to the web; a support arrangement on which said guide track is mounted and arranged to support the welding head overthe web; a pair of guides carried by the welding head and each engageable along a respective one of the side edges of the rib; a pair of welding torches carried by the welding head and each arranged to follow a respective one of the guides, during movement of the welding head along the rib, and to carry out welding along the respective side edge;; an inverted channel-shaped frame on which said welding head is mounted; a slider on which said frame is mounted and which is mounted for movement along said guide track; means mounting each guide and respective welding torch on the welding head for joint movement between an operative position along a respective side of the rib and an inoperative position permitting lateral movement of the welding head relative to the rib; lateral adjustment means connecting the guide track to the support arrangement and operable to permit of automatic relative lateral adjustment of the guide track as the guides of the welding head follow the line of the rib; and further adjustment means connecting the guide track to the support arrangement and operable to permit of automatic relative up and down movement of the guide track as the guides of the welding head engage the web they follow the line of the rib.

2. A welding machine according to claim 1, in which the welding head is mounted on the slider by means of an elongate support which is pivotally mounted on the slider.

2. Awelding machine according to claim 2, in which the support is adjustable to vary its inclination relative to that of the slider and the guide track, thereby to vary the positioning of the guides and respective welding torches relative to the rib and web.

4. A welding machine according to claim 3, in which the inclination of the support to the slider is adjustable within the range of 5 to 15 .

5. A welding machine according to claim 4, including an adjustable cam mechanism operative between the elongate support and the slider in order to adjust the inclination of the support.

6. A welding machine according to any one of claims 2 to 5, in which each of said mounting means comprises an elbow pivotally mounted at its upper end on a lower end of a respective limb of the inverted channel-shaped frame and carrying a respective guide at its lower end.

7. A welding machine according to claim 6, in which each welding torch is rigidly coupled with the lower end of the respective elbow.

8. A welding machine according to any one of claims 2 to 7, in which a wire feeding device and supply drums are mounted on said elongate support and arranged to supply welding wire to the welding torches.

9. A welding machine according to any one of the preceding claims, in which the guide track comprises a rack.

10. A welding machine according to claim 9, including a tractor device engageable with said rack and coupled with the slider in order to draw the welding head along the length of the rib.

11. A welding machine according to claim 1 and substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.