A device for supplying welding additives when joining the ends of strip materials using welding techniques.

Abstract

The present invention provides a device for supplying welding additives when joining the ends of strip materials by welding techniques. [Solution] Between pilot rollers (1) for positioning the end of the strip material to be welded (9), supply nozzles (5, 5') for wire-type welding additives are positioned at an angle (α) with respect to the alignment (10) of the welding head (2). A first supply nozzle (5) for a first wire-type welding additive (4) and a second supply nozzle (5') for a second wire-type welding additive (4') are positioned and movable relative to each other so that each supply nozzle (5, 5') can be linearly (6, 6') delivered into the area of ​​the welding zone (11). The first and second supply nozzles (5, 5') are aligned by being rotated relative to each other by a predetermined angle, and the first and second supply nozzles (5, 5') allow each welding additive (4, 4') to be melted by the welding head (2).

Description

Technical Field

[0001] The present invention relates to an apparatus for supplying a welding filler material when joining strip ends by a welding technique according to claim 1.

[0002] In the range of processing of metal sheet materials in the form of strip materials wound up to form coils, the joining of strip materials to be continuously processed by laser welding and also by resistance welding is widely known. The strip materials are assembled, for example, in a rolling mill, mainly from relatively long individual strip pieces that are wound up for a pickling process or a similar processing step, and are thus processed continuously. For this purpose, the strip ends of the strip materials to be processed successively are welded to each other. Such a welding station is mainly located at the inlet of the process line for processing the strip materials. To ensure a continuous processing process of the strip materials, the machine welds the strip end of the strip material currently in the processing process, for example, the strip end in the pickling solution or in the rolling mill, to the strip start end of another strip material to be processed subsequently. For the pretreatment of the weld seam of the strip material to be welded, generally a shear cut is performed, and by this shear cut, smooth and parallel strip ends are formed in the region to be welded later.

[0003] In this case, not only strip materials of the same material and the same material quality have to be joined to each other, but also strip materials of different materials, metal sheet thicknesses, and surface qualities have to be joined to each other. As a result, especially when processing conventional construction steel materials and ferritic special steels in a strip processing line, the use of various welding filler materials is necessary.

[0004] In this case, the welding apparatus typically consists of a base frame, to which a clamping table is attached for positioning and clamping the strip ends to be positioned relative to each other. A C-shaped frame (C-shaped carriage) runs along the base frame, and this C-shaped frame houses cutting and welding components, including devices for preheating and postheating the welding area. The C-shaped frame moves above the areas of the strip ends positioned front to back, moving the welding apparatus along adjacent strip ends, thereby welding these strip ends to each other. In addition to laser welding, resistance welding methods such as roll seam welding or spot welding are also used in this type of welding apparatus.

[0005] In the welding zone, pilot rollers are positioned above the welding zone, roughly in a V-shape and aligned with each other. These pilot rollers, along with rollers positioned below the welding zone, align the strips to be joined and maintain their relative positions and orientations during welding. In this case, these pilot rollers continuously roll along the welding seam during the welding process of the strips. In this scenario, the actual welding equipment, such as a laser welding head, is usually engaged from above within the free space between the V-shaped pilot rollers, thereby directing the welding energy directly into the welding zone. In this case, the configuration space between the pilot rollers for accommodating the welding equipment and other functions is significantly limited.

[0006] For preheating and postheating of the welding area, additional heating devices are typically used. These heating devices are positioned near each welding zone to ensure precise temperature control of the welding zone, further restricting access to the actual welding zone for the welding head and the welding additives required for welding the strip material. Such welding additives are typically delivered as wire wound on a roll from a wire supply unit to the welding zone by a nozzle positioned near the welding zone, where they are melted during welding. Because direct supply by the welding head is impractical in the extremely limited space between pilot rollers, the wire supply unit is usually positioned at an acute angle to the direction of feed of the pilot rollers. For this reason, the supply nozzle is also positioned between the pilot rollers, but usually rotated by a predetermined angle relative to the welding head coming from above. Due to the extremely limited space and the melting characteristics of the welding additives, the supply nozzle is optimally positioned between the pilot rollers at an angle of approximately 48° to 52° relative to the perpendicular or alignment of the laser head.

[0007] However, nowadays, when welding various thin sheet metal strips made of conventional building steel or ferritic special steel to each other, a wide variety of welding additives must be used. This requires modifications to conventional welding stations, such as replacing the wire wound in the wire supply unit, feeding it through a nozzle, and sending the wire-like welding additive to the welding zone. However, such modifications require modification time, during which the entire facility becomes unusable, potentially resulting in costly downtime for the entire system. Similar downtime is required when rollers for the wire-like welding additive are installed and replaced. This does not always occur during periods when welding is not being performed, or the replacement process must be completed before the rollers finish rolling during such idling time, resulting in leftover welding additive material that cannot be used further.

[0008] It is already known that two wire feeders can be used in parallel during welding to introduce a larger amount of additive into the molten material. However, in this case, both wire feeders operate simultaneously, and there are virtually no limitations on the configuration space.

[0009] Therefore, the object of the present invention is to provide an apparatus that can solve the problem of loading the same or different welding additives into the welding zone with minimal exchange time, even in narrow space conditions when welding the ends of a strip material.

[0010] The means for solving the problem according to the present invention is obtained by the feature of claim 1 in cooperation with the feature of a higher-level concept. Another advantageous configuration of the present invention is described in the dependent claims.

[0011] The present invention relates to a device for supplying welding additives when joining strip ends by welding, and begins with a device in which a supply nozzle for a wire-shaped welding additive is positioned between pilot rollers for positioning the strip ends to be welded, and is rotated at an angle to the alignment of the welding head. Such a device in a broader sense is further developed by the present invention by which a first supply nozzle for a first wire-shaped welding additive and a second supply nozzle for a second wire-shaped welding additive are positioned and movable relative to each other so that each supply nozzle can be linearly fed into the area of ​​the welding zone, the first and second supply nozzles are aligned by rotating them relative to each other by a predetermined angle, and the first and second supply nozzles can linearly feed each other alternately into the area of ​​the welding zone so that each welding additive can be melted by the welding head. The arrangement of the two supply nozzles according to this invention allows, on the one hand, to alternately load two different welding additives depending on the type of strip material to be welded, but on the other hand, it is also possible to use the same welding additive in both supply nozzles to increase the volume of welding additive to be supplied. In both cases, while the wire-like welding additive in one of the supply nozzles is being replaced or filled, the welding additive in the other supply nozzle can be melted, which has the advantage of reducing or completely avoiding downtime. In this case, the two supply nozzles are positioned to enter each other at different angles into the free space between the V-shaped pilot rollers, due to the extremely narrow space between the V-shaped pilot rollers. However, in this case, only one of the two feed nozzles is actually delivered into the free space between the V-shaped pilot rollers to the extent that the welding additive guided inside can reach the area of ​​the welding zone and melt there, while the other feed nozzle is positioned pulled back from the free space between the V-shaped pilot rollers, freeing up space for the other feed nozzle that it is engaged with.This achieves greater flexibility for two different feeding possibilities compared to known single-type feeding nozzles, even though it requires only the virtually unincreased available space between the pilot rollers, which are arranged in a V-shape relative to each other, for two feeding nozzles that can be used alternately.

[0012] Particularly advantageous is that the first and second feed nozzles are aligned with respect to the welding head alignment at different angles relative to the ideal angle of a single feed nozzle arrangement between the pilot rollers, on either side of this ideal angle. This means that the welding apparatus concept does not need to be changed for a single feed nozzle arrangement, and only minor modifications are required without making the use of two feed nozzles impossible due to space constraints. In this case, in an alternative configuration, the first feed nozzle may be aligned with respect to the welding head alignment at a smaller angle and the second feed nozzle at a larger angle, so that both feed nozzles are positioned on either side of the ideal arrangement of a single feed nozzle, alternately engaging in the space between the V-shaped pilot rollers, thereby allowing the welding additive of the engaged feed nozzles to melt in the welding zone. For collision avoidance, the feed nozzles may be equipped with lead sensors and permanent magnets, which can detect and prevent the feed nozzles from being in an unacceptable position.

[0013] It is particularly advantageous if the first supply nozzle is positioned at an angle of 42° to 46° relative to the welding head alignment, and the second supply nozzle is positioned at an angle of 53° to 57° relative to the welding head alignment, and they are rotated and aligned relative to each other. In this case, the angle that has been recognized as ideal for positioning a single supply nozzle is in the range of 48° to 52° relative to the welding head alignment. Therefore, in the present invention described above, the first supply nozzle is positioned at a slightly steeper angle than the angle that has been recognized as ideal for positioning a single supply nozzle, and the second supply nozzle is positioned at a slightly flatter angle.

[0014] In the first configuration, different welding additives can be introduced into the welding zone area by multiple supply nozzles, each depending on the material of the strip material to be welded to each other.

[0015] However, in an alternative configuration, the same welding additive can be supplied to the welding zone area by multiple supply nozzles, thereby doubling the volume of welding additive supplied.

[0016] However, in both of the above embodiments, it is also conceivable that, during welding, the welding additive from one supply nozzle can be replaced without any downtime of the equipment while the welding additive from the other supply nozzle is melting. This eliminates the need for downtime of the equipment that was previously required for replacing the necessary welding additive or for refilling the supply nozzles with welding additive.

[0017] It is advantageous if the first and second feed nozzles are positioned, held, and driven in the area between the pilot rollers so that they can alternately and linearly advance into the area of ​​the welding zone from the retraction position and then be retracted again. This prevents the feed nozzles, and by extension the portions of each feed device located downstream of the feed nozzles, from interfering with each other, particularly in the narrow structural space between the V-shaped arrangement of the pilot rollers.

[0018] If the material properties of the welding additives can preferably be detected via induction, thereby ensuring the elimination of the use of incorrect welding additives, this contributes to operational reliability. For this purpose, the ferromagnetism of each welding additive can be detected, for example, by induction, via a suitable sensor. This allows for verification of whether the welding additive material is ferritic or austenitic, and whether the correct welding additive is appropriately selected for welding the strip ends present each time.

[0019] Particularly preferred embodiments of the apparatus according to the present invention are shown in the drawings. [Brief explanation of the drawing]

[0020] [Figure 1] A purely theoretical diagram of the arrangement of two supply nozzles 5, 5' between the pilot rollers 1 of a known welding apparatus for joining strip ends 9, showing the position where the first supply nozzle 5' is feeding wire-like welding additive 4' into the area of ​​the welding zone 11. [Figure 2] Figure 1 shows an alternative arrangement of the supply nozzles 5, 5' between the pilot rollers 1, in which case the second supply nozzle 5 is feeding the wire-shaped welding additive 4 into the area of ​​the welding zone 11.

[0021] Figure 1 shows a purely theoretical diagram of the arrangement of two supply nozzles 5, 5' between pilot rollers 1 arranged at an angle 8 to each other in a V-shape, of a welding apparatus known for joining strip ends 9, with the first supply nozzle 5' in the position where it is feeding wire-like welding additive 4' into the area of ​​the welding zone 11.

[0022] A welding apparatus known in itself is used in a passing apparatus, for example, to join the ends 9 of a strip material, and will be described only when necessary to understand the present invention. The welding apparatus here has a welding head 2 formed as, for example, a laser welding head, which directs a laser beam 10 vertically from above into the area of ​​the welding zone 11, thereby intensely heating the metal sheet 9 to be joined in the area of ​​the welding zone 11. The metal sheet 9 is aligned and temporarily fixed to each other by two pilot rollers 1 positioned above the metal sheet 9 in a V-shape relative to each other. Below the metal sheet 9, there is a type of opposing retaining roller, which is not further shown in Figure 1, and the pilot rollers 1 press the metal sheet 9 against this opposing retaining roller.

[0023] The welding additives 4,4' required for welding are supplied in the form of wire-like sections. These wire-like sections are wound onto a roll outside the drawing of Figure 1 and fed to supply nozzles 5',5 from a feeder, which is not shown in detail. Of these supply nozzles, supply nozzle 5' is located near the welding zone 11, from which the material exits supply nozzle 5' and is melted under the action of the laser beam 10.

[0024] In conventional welding equipment, due to the limited space between the pilot rollers 1, only one such supply nozzle 5 is provided to deliver the wire-shaped welding additive 4 to the welding zone 11.

[0025] For welding various strip materials, it can be advantageous to deliver different welding additives 4,4' to the welding zone 11 each time, without the need to completely refill the supply nozzle 5 with welding additive 4, which is usually costly and undesirable and results in downtime of the welding equipment. Such a supply nozzle 5 is usually positioned at an angle α relative to the incident direction of the laser beam 10, because this allows for optimal supply of the wire-like welding additive 4.

[0026] However, due to the extremely narrow space between the pilot rollers 1, which are arranged in a V-shape, it is not possible to simply use two supply nozzles 5 to supply wire-shaped welding additives 4, 4' either selectively or, in some cases, additionally.

[0027] Therefore, in order to solve this problem, it is proposed to realize the inventive arrangement of two alternatively operable supply devices for the welding filler materials 4, 4' by arranging two identically configured and functioning supply nozzles 5, 5' which can be pivoted relative to each other and which can each be operated alternately. The basic idea is that only one of the supply nozzles 5 or 5' at a time penetrates between the pilot rollers 1 to such an extent that it is located within the region of the welding zone 11, and this supply nozzle then releases the wire-shaped welding filler material 4 or 4' there into the welding zone 11, thus using the available little assembly space between the pilot rollers 1 arranged in a V-shape relative to each other twice as it were. In the case where the other welding filler material 4' or 4 is to be processed, the supply nozzle 5 or 5' which has been used up to that point is pulled back between the pilot rollers 1 arranged in a V-shape relative to each other until a space for the other supply nozzle 5' or 5 is created each time, and now this other supply nozzle can release the welding filler materials 4, 4' guided thereby into the welding zone 11. This arrangement can also be used to double the processable capacity of the same welding filler materials 4, 4', in which case the already described exchange of the supply nozzles 5' or 5 is utilized for this purpose.

[0028] To achieve such an alternating operation of the supply nozzles 5 or 5', the supply nozzles 5 or 5' each comprise a feed device 6, 6' (not shown in detail) which can move the supply nozzles 5 or 5' in the feed directions 3, 3' towards the welding zone 11 or away from the welding zone 11 respectively. Lead contacts and permanent magnets (not shown any further) which can detect each position of the supply nozzles 5 or 5' relative to the welding zone 11 and can prevent mutual collisions of the supply nozzles 5 or 5' are attached to the rear side of the feed devices 6, 6'.

[0029] In order to detect the material properties of each welding filler 4, 4' and, in some cases, of the strip end 9, and to avoid the use of incorrect welding fillers 4, 4', the ferromagnetic properties of each welding filler material 4, 4' and, in some cases, of the strip end 9 can be detected inductively, for example, via corresponding sensors such as magnetic indicators 7, 7'. Thereby, it is possible to check whether the material of the welding filler 4, 4' and / or the strip end 9 is a ferritic or austenitic material, and whether the respective suitable welding filler 4, 4' is appropriately selected for the welding of the strip end present each time.

[0030] In FIGS. 1 and 2, the above-described two positions of the supply nozzle 5 or 5' can be recognized. In this case, it can also be recognized that the supply nozzles 5 or 5' are arranged inclined with respect to each other on both sides of a swivel position near the angle α indicating the ideal adjustment swivel position of the supply nozzle 5. The supply nozzle 5' is swiveled by an angle α2 which is slightly smaller than α in this case. The supply nozzle 5 is swiveled by an angle α1 which is slightly larger than α in this case.

[0031] Typical values for these angles can be, for example, as follows: Angle α, ideal supply angle, for example 48° - 52° Angle α1, enlarged angle in the clockwise direction, for example 53° - 57° Angle α2, reduced angle in the counterclockwise direction, for example 42° - 46°.

Explanation of reference numerals

[0032] 1 Pilot roller 2 Welding head 3, 3' Adjustment direction of supply nozzle 4, 4' Tip of welding wire 5, 5' Supply nozzle 6, 6' Feeding device 7, 7' Magnetic indicator 8 Open area between pilot rollers 9 Metal sheet 10 Laser beams 11 Welding Zones

Claims

1. A device for supplying welding additive when joining strip ends (9) by welding, wherein supply nozzles (5, 5') for a wire-shaped welding additive (4) are positioned between pilot rollers (1) for positioning the strip ends (9) to be welded, and are rotated at an angle (α) with respect to the alignment (10) of the welding head (2), A first supply nozzle (5) for a first wire-shaped welding additive (4) and a second supply nozzle (5') for a second wire-shaped welding additive (4') are arranged relative to each other and are movable so that each of the supply nozzles (5, 5') can be linearly (6, 6') delivered into the area of ​​the welding zone (11). The first and second supply nozzles (5, 5') are aligned by rotating them relative to each other by a predetermined angular value. The first and second supply nozzles (5, 5') can alternately deliver each of the welding additives (4, 4') into the area of ​​the welding zone (11) in a linear manner (6, 6') only, so that each of the welding additives (4, 4') can be melted by the welding head (2). An apparatus characterized by the following features.

2. The apparatus according to claim 1, wherein the first and second supply nozzles (5, 5') are swung relative to the ideal angle (α) of the arrangement of one supply nozzle (5) between the pilot rollers (1), on both sides of the ideal angle (α), and are aligned with respect to the alignment of the welding head (2).

3. The apparatus according to claim 1, wherein the first supply nozzle (5') is aligned with the welding head (2) at a smaller angle (α2) and the second supply nozzle (5) is aligned with the welding head (2) at a larger angle (α1) relative to each other.

4. The apparatus according to claim 1, wherein, relative to the alignment of the welding head (2), one of the supply nozzles (5') is rotated at an angle (α2) of 42° to 46°, and the other supply nozzle (5) is rotated at an angle (α1) of 53° to 57°, and the apparatus is aligned with respect to these angles.

5. The apparatus according to claim 1, wherein the supply nozzles (5, 5') can supply different welding additives (4, 4') to the region of the welding zone (11).

6. The apparatus according to claim 1, wherein the supply nozzles (5, 5') can supply the same welding additive (4, 4') to the area of ​​the welding zone (11).

7. The apparatus according to claim 1, wherein, during welding, while the welding additive (4') from one of the supply nozzles (5') is being melted, the welding additive (4) from the other supply nozzle (5) can be replaced without any downtime of the equipment, and vice versa.

8. The apparatus according to claim 1, wherein the first and second supply nozzles (5, 5') are positioned, held, and driven (6, 6') in the area between the pilot rollers (1) so that they can be alternately fed linearly (3, 3') from a retraction position into the area of ​​the welding zone (11) and then retracted again.

9. The apparatus according to claim 1, wherein the material properties of the welding additive (4, 4') can preferably be detected via induction.

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