GB2062525A

GB2062525A - Improvements in or relating to welded joints

Info

Publication number: GB2062525A
Application number: GB8028443A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-09-04
Filing date: 1980-09-03
Publication date: 1981-05-28
Also published as: CH649488A5; FR2464119A1; ATA408780A; BE884858A; DE2935692C3; AT378493B; NL8004799A; DE2935692B2; DE2935692A1

Abstract

A welded joint between two structural members, for example, a door frame (1) (3), wherein at least one (3) of the members exhibits an edge (4) in the joint region. The exhibited edge (4) of the structural member (3) is castellated or meandering whereby to allow greater tolerance in the positioning of the welding apparatus so that the weld seam centre may locate anywhere in the zone 9. <IMAGE>

Description

SPECIFICATION Improvements in or relating to welded joints This invention relates to welded joints.

The invention is particularly concerned with welded joints between a door frame and a transport angle provided in the floor region thereof.

It frequently occurs that two structural members must be welded to each other in such a way that the weld seam is directed along the edge of one structural member. If it is wished to conduct such welding operations for example within the compass of assembly line production with automatic control as far as possible, then it needs considerable precision to direct the weld seam exactly so that the edge region of one structural member can be welded to the adjoining, for example plane region, of the other structural member. Therein it is to be taken into consideration that the weld seam is directed as narrowly as possible, in particular when external material is supplied as welding material.

Therein it is less difficult to guide the welding apparatus correspondingly exactly, rather, in the course of the assembly line operation meant here, the placing of the two members relative to each other, the dimensional measurements thereof and the like are subjected to a fluctuation which causes the position of the edge region in relation to the welding tool to shift. Furthermore, it is to be taken into consideration that with such production operations vibrations occur, which again lead to a deviation from the required zone. Attention is therefore to be paid to a few criteria if it is wished to achieve the desired precise and narrow weld seam shape. In practice, these conditions can scarcely be achieved.

It has already been attempted to meet these precision requirements by controlling the welding apparatus in a kind of oscillating movement, guided transversely to the edge shape. Thereby is covered transversely to the edge shape a welding region which is so great that variously displaced positionings of the members, vibrations and the like can be averted, and yet an altogether relatively wide weld seam is obtained and considerable effort must be made above all, with respect to guiding of the welding apparatus. This concerns the mechanical guide members as well as the drive required to move the welding apparatus. Ensuring the welded joint requires in this way an excess of welding material, an excess of energy for welding and guiding the apparatus and in particular also increased expenditure of time to perform the "oscillating seam" compared to a straight seam.

Basically it is possible to fix the two structural members to each other respectively by an edge region. To that extent the considerations made here apply too. Further, the edge shape can by all means also be curved, in such a way that a welding apparatus can follow this edge shape. In such a case, the requirements of precise positioning of the structural members to be welded together and of the welding apparatus in relation to each other may be still higher than with a straight edge shape.

It is the object of the invention to provide a welded joint of the kind in question, in which without special precision requirements of positioning of the structural members and welding apparatus, a weld seam is always performed so that the two members are joined together reliably.

According to one aspect of the invention, a welded joint between two structural members, at least one of which exhibits an edge in the joint region, is characterised by said edge being discontinuous.

According to another aspect of the invention, a welded joint between two structural members, in particular a door frame and a transport angle provided in the floor region, at least one of which exhibits an edge in the joint region, wherein the weld extends in the region of this edge, is characterised by the fact that the structural member with the edge is constructed in the joint region with a discontinuous edge shape.

Interruption of the edge shape is to be understood very generally to the effect that an edge shape of the boundary arises, which on relative movement between the structural members on the one hand and the welding apparatus on the other hand is intersected by the weld seam to be performed, in such a way that even with correspondingly high positioning tolerances, the weld seam in every case reaches corresponding regions of both structural members.

The interruptions in the edge shape can therein be achieved both by projections in relation to the normal edge shape and by recesses. Recesses will always be provided in preference when the corresponding structural member is a profiled member.

According to the invention, there is achieved the result that in spite of a narrow weld seam, both structural members are always attained. In the extreme case, this may appear such that the seam is performed in the outermost edge region, and hole-like structures remain of the recesses. In the other extreme case, and therefore when the structural members extend with respect to the edge shape in relation to the welding apparatus displaced in the other direction, a weld seam which extends in the root region of the recesses is performed, so that in the outermost edge region an irregular shape remains visible. It is recognised that the normal edge shape in relation to the welding apparatus may vary in a relatively wide zone without the reliability of the welded joint suffering and without any outlay having to be made on welding material, guiding of the welding apparatus, and the like.According to the order of magnitude of the recess, it is in hand how precisely positioning of the structural members relative to the welding apparatus must be executed. Therewith is obtained in practice very effective aid for producing a reliable welded joint of the members in question, with as little outlay as possible.

Further developments of the invention appear from the subsidiary claims.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein Figures 1 a and 1 b are, respectively, fragmentary front and side views which illustrate the problem; and Figures 2a and 2b are similar views which illustrate the development of a welded joint according to the invention.

With reference to Figures 1 a and 1 b, the example reproduced in these drawings shows the welded joint between the lower region of a door frame 1 with set-back stop zone 2 and a so-called transport angle 3 which encompasses the associated lower edge region of the frame and is welded to the frame by its arm lying in the plane of the frame. In particular, the transport angle does not therein have to fulfil any special precision from its function, for which reason it is desired to use profile material as cheap as possible. In this way there results a first possibility of position shift of the edge shape 4 in the joint region on account of different arm heights of the angle.A second imprecision results with respect to positioning in relation to the welding apparatus 5, and finally there results as a third possibility of imprecision, fluctuations such as are unavoidable on account of assembly line transport or the like.

In Figures 1 a and 1 b are shown the conditions when working with continuous edge region 4.

There results only a very narrow zone in which the weld seam is effectively applied, this being such that it welds the end face region of the edge of the transport angle to the adjoining surface region of the frame 1 in the joint region 8. For this purpose, the welding apparatus 5 is directed at a corresponding angle onto this end face region of the edge of the angle. It is perceived in Figure 1 b that already slight shifts in position of the end face of the edge region 4 in relation to the welding apparatus 5 lead to positioning in which the weld seam no longer or no longer sufficiently covers the two zones to be welded.

Figures 2a and 2b show a construction of the discontinuous edge shape 7 according to the invention, namely interrupted by recesses 6, so that altogether a meander-like or castellated shape results in the edge region of the corresponding arm of the transport angle 3. On the basis of the possible weld seam centres 9 reproduced in broken lines, it is perceived that a substantially wider zone perpendicularly to the straight edge shape of the transport angle 3 is available for welding. The weld seam can therefore, as shown in Figures 2a and 2b, directly join the edge region or here the remaining edge regions 4 between the recesses 6 to the frame 1, but the weld seam can also be performed somewhat deeper, in such a way that the weld seam extends to a large extent in the root zone of the recesses.The structural members and the welding apparatus will therefore be positioned in such a way relative to each other that in standard cases the centre zone of the weld seam centres drawn is covered. Thence result then according to the drawings recognisably upper and lower tolerance limits.

A further advantage also consists in that the welding apparatus 5 no longer has to be aligned at a predetermined angle to the end face of the edge.

It can just as well be aligned at a right angle to the arm surface or frame surface in the joint region.

Only if it is wished to utilize the upper tolerance range fully, is it recommended to maintain the angle apparent from Figure 2b, so that welding material is forced into the recesses between the crenellated peaks. There results therefore the possibility of adjusting alignment of the welding apparatus in an order of magnitude of approximately 450 as desired.

Altogether there is achieved a reliable welded joint in the case of low alignment precision and without the advantages with respect to time, energy and outlay for guiding the welding apparatus, which apply to guiding only a straight seam, being abandoned.

Claims

1. A welded joint between two structural members, at least one of which exhibits an edge in the joint region, wherein said edge is discontinuous.

2. A joint according to Claim 1, wherein said edge is castellated.

3. A joint according to Claim 1 or 2, wherein said edge is of meandering form.

4. A joint according to Claims 1, 2 or 3, wherein said discontinuous edge is provided for optional right-left stop motion on two opposed edges of the edged structural member.

5. A welded joint between two structural members, in particular a door frame and a transport angle provided in the floor region, af least one of which exhibits an edge in the joint region, wherein the weld extends in the region of this edge, characterised by the fact that the structural member with the edge is constructed in the joint region with a discontinuous edge shape.

6. A joint according to Claim 5, characterised by the fact that the edge shape exhibits recesses.

7. A joint according to Claim 5 or 6, characterised by the fact that the edge shape is constructed in meandering form.

8. A joint according to any one of Claims 5, 6 or 7, characterised by the fact that the discontinuous edge shape is provided for optional right-left stop motion on two opposed edges of the edged structural member.

9. A door frame incorporating a welded joint according to any one of Claims 1 to 8.

10. A welded joint, substantially as hereinbefore described with reference to Figures 2a and 2b of the accompanying drawings.

1 1. A door frame, substantially as hereinbefore described with reference to Figures 2a and 2b of the accompanying drawings.