EP1935524A1 - Device for flame straightening - Google Patents

Abstract

The device e.g. multi-nozzle straightening burner (100), has two nozzles (10, 20) arranged below a non-vanishing angle (W) to each other and divergingly arranged in direction of flow. The nozzles are arranged at a gas distribution pipe (34) that is formed in a cross beam shape. The gas distribution pipe is assigned to a retainer (30), and the retainer is attachable on a surface (S) of a component or workpiece (B) and/or is movable on the surface of the component or workpiece. An independent claim is also included for a method for flame-straightening.

Description

Technical area

The present invention relates to a device for flame straightening according to the preamble of claim 1.

State of the art

Metallic structures, in particular steel structures, which have been produced by welding and / or by forming, generally have deviations in form and / or deviations which must be compensated by subsequent straightening. The most common method of straightening metallic parts is so-called flame straightening. Flame straightening is often used for technological or industrial safety reasons.

To P. Bernhard, G. Schreiber, "Methods of Autogenous Engineering", German publishing house for welding technology, Dusseldorf 1973 , is an essential prerequisite for successful flame straightening a faster limited heat input through particularly hot intense flames. It is therefore advisable to use fuel gas-oxygen flames, in particular acetylene-oxygen flames.

Although it is known that a thermal treatment not only by means of a fuel gas-oxygen flame, but in principle with any technically available heat source, such as arc, electrical resistance heat, induction heat, light heat, laser beams, ion beams or electron beams, is possible. However, in the field of thermal straightening, flame straightening has asserted itself.

When using arcs for straightening, the arc initiation point on the workpiece surface causes localized smudges, in particular may be considered disadvantageous in terms of strength. A straightening of workpieces by resistance or induction heating is very complex in the implementation.

By contrast, flame straightening with a fuel gas-oxygen flame has been used for decades and can also be automated to eliminate changes in shape that result in the manufacturing process of components.

Such as the " Handbuch der Flammrichttechnik ", book series welding technology, volume 124, DVS-Verlag, Dusseldorf 1995 or the prospectus " Tips for practitioners. Flame straightening "(June 2005 issue) ) can be removed from the company Linde, the component is heated during Flammrichten targeted locally to the plastic area; as a result of impaired thermal expansion, a permanent compression of the component occurs. During cooling, there is a reduction in the workpiece, which leads to the desired shape change.

• Wärmepunkt: Die Anwendung erfolgt bei Blechfeldern, Rohren und Wellen. Der Wärmepunkt ist so klein wie möglich zu halten.
• Wärmestrich: Die Anwendung erfolgt zum Beheben von Winkelverzug, zum Beispiel mittels Gegenwärmen von Kehlnähten. Der plastische Bereich darf höchstens bis zu einem Drittel in die Blechtiefe hineinreichen. Die Wärmepunktreihe biegt schwächer als der Wärmestrich.
• Wärmekeil: Die Anwendung erfolgt bei starken Verbiegungen, zum Beispiel von Profilen und von Lamellen. Der Wärmekeil ist lang und schmal. Es wird von der Spitze ausgehend bis hin zur Grundfläche gleichmäßig auf Richttemperatur gewärmt.
• Wärmeoval: Die Anwendung erfolgt an Rohren, zum Beispiel nach dem Anschweißen von Stutzen. Das Wärmeoval wird durchgewärmt und in Längsrichtung der Rohrachse angeordnet.

Different types of heating are possible for flame straightening, which can also be meaningfully combined depending on the component shape:

• Heat point: The application is applied to sheet metal fields, pipes and shafts. The heat point should be kept as small as possible.
• Heat screed: The application is used to correct angular distortion, for example by counterheating of fillet welds. The plastic area may extend at most up to a third into the sheet depth. The heatpoint series bends weaker than the heat screed.
• Heat wedge: The application is made for strong bends, for example of profiles and lamellae. The heat wedge is long and narrow. It is heated from the tip to the base evenly to the straightening temperature.
• Heat oval: The application is made on pipes, for example after welding on nozzles. The heat oval is warmed through and arranged in the longitudinal direction of the tube axis.

It is extremely important in Flame straightening the point of reference, so the point at which a heat input is necessary to eliminate the change in shape can meet exactly, because only then reaches the desired directional result and the change in shape is eliminated.

• Einflammen- oder Eindüsenbrenner: Hierbei handelt es sich um den gebräuchlichen Brenner zum Richten mit Wärmepunkten, -strichen, -keilen oder -ovalen.
• Mehrflammenbrenner: Ein Mehrflammenbrenner besteht aus einer Düse mit mehreren Einzelflammen. Mehrflammenbrenner werden in der Regel zum Richten mit Wärmestrichen, -keilen und -ovalen an Werkstücken mit einer Wanddicke ab etwa zwanzig Millimetern eingesetzt.
• Mehrdüsenbrenner, in nicht umschaltbaren und umschaltbaren Ausgestaltungen, beispielsweise umschaltbare 2-, 3- und 5-Düsenbrenner: Ein Mehrdüsenbrenner besteht aus mehreren Düsen mit jeweils einer Flamme. Mehrdüsenbrenner werden z.B. zum Beseitigen von Winkelverzug und zum Richten von Beplankungen im Schiffbau und von Blechkonstruktionen eingesetzt. Die verwendeten Düsen sind zum Gasaustrittsort hin meist konisch zulaufend; jedoch werden auch zylindrisch verlaufende Düsen eingesetzt.
• Sonderbrenner, etwa vom Typ LINDOFLAMM der Firma Linde: Diese werden in Form und in Leistung für die jeweilige Flammrichtaufgabe ausgelegt und kommen zum Beispiel beim Richten von Großrohren oder von dickwandigen Werkstücken zum Einsatz.

With regard to the equipment used in flame straightening, it is possible to use as flame direction burners as a function of the particular application and as a function of the thickness of the workpiece (cf. Fig. 1 ):

• Flame or injector burner: This is the common burner for straightening with heat points, smears, wedges or ovals.
• Multi-flame burner: A multi-flame burner consists of a nozzle with several individual flames. Multi-flame burners are usually used for straightening with heat screeds, wedges and vaults on workpieces with a wall thickness from about twenty millimeters.
• Multi-nozzle burners, in non-reversible and switchable configurations, for example reversible 2-, 3- and 5-nozzle burners: A multi-nozzle burner consists of several nozzles, each with a flame. Multi-nozzle burners are used, for example, for eliminating angular distortion and for directing skins in shipbuilding and sheet metal constructions. The nozzles used are usually tapered towards the gas outlet; however, cylindrical nozzles are also used.
• Special burners, such as the LINDOFLAMM from Linde: These are designed in shape and performance for the respective flame straightening task and are used, for example, when straightening large pipes or thick-walled workpieces.

The size of the Flammrichtbrenners is determined by the type of material and by the thickness of the sheet to be machined. For sheets up to about three millimeters, for example for structural steel, the burner size is selected as in welding.

The gas supply is to be designed according to the size of the flame jet burner and depending on the extent of the straightening work. Thus, for both the fuel gas, in particular for the acetylene, as well as for the oxygen, the coupling of several gas cylinders may be required.

Due to the increasingly required processing of thin-walled metal sheets and profiles in the metalworking industry, changes in the shape of the components often occur during the manufacturing process; these Shape changes occur in particular due to the heat input during welding processes.

Through the use of new welding processes, such as laser welding or laser hybrid welding, new seam geometries have been developed, which also entail a changed shape change behavior.

Such changes in shape can not be eliminated with conventional flame direction burners or only with increased effort.

Presentation of the present invention: object, solution, advantages

Based on the disadvantages and inadequacies set out above, and in appreciation of the prior art outlined, the present invention has the object, a device for flame straightening of the type mentioned in such a way that in the manufacturing process of a component or workpiece resulting form changes in a simple and efficient manner can be eliminated. In particular, it should be possible with the device to be specified, to work close to each other directivity points in a simple manner and to obtain a judicial success.

This object is achieved by a device for flame straightening with the features specified in claim 1. Advantageous embodiments and expedient developments of the present invention are characterized in the subclaims.

Thus, the present invention is based on the provision of a flame straightening device designed as, in particular switchable, multi-nozzle burners, for example two-nozzle burners, whose nozzles are arranged relative to one another such that the distance between the nozzles at the gas outlet location is lower than in conventional flame-screening devices.

In the case of the flame straightening device which can be labeled as flame jet burner, according to the invention the nozzle spacing at the gas outlet point is reduced so that it is at the impact point the flames on the surface of the workpiece is only about twenty millimeters (compared to about thirty millimeters conventionally).

In order to prevent excessive mutual heating of the nozzles, which occurs at too small a distance of the nozzles to each other, these nozzles are at a non-vanishing angle, that is at an angle not equal to zero degrees, in particular at an angle of about one degree to about sixty degrees, preferably at an angle of about three degrees to about thirty degrees, more preferably at an angle of about five degrees to about fifteen degrees, for example, at an angle on the order of about ten degrees, to each other.

Such a V-shaped or mutually angled, and in this case in particular in the flow direction diverging arrangement of the nozzles shows particular advantages in very close to each other Flammrichtpunkten.

In an arrangement with more than two nozzles, the nozzles may advantageously be arranged either in one plane or three-dimensionally. If more than two nozzles are used, the number of simultaneously editable alignment points also increases. In the case of arrangements with more than two nozzles, in particular an arrangement of several Vs in one plane or of several Vs in parallel planes is recommended. The arrangement of the nozzles always results from the position of the directional points and the angular arrangement of the nozzle ensures that the distance between the nozzles is always sufficient.

The multi-nozzle, in particular two-nozzle Flammrichtbrenner, according to the present invention, a cost effective and effective elimination of changes in shape in a component is made possible, wherein the changes in shape have very close adjacent directing points. Such changes in shape result, for example, when attaching a weld.

The present invention further relates to a method for flame straightening, characterized by the use of at least one device according to the kind set forth above. With the method according to the invention, the heat input during flame straightening in the component is thus advantageously concentrated at the straightening points.

Finally, the present invention relates to the use of at least one device according to the above-described type in flame straightening thin-walled sheets or thin-walled profiles; Thus, the present invention is particularly useful in the thin sheet sector, for example, in the machining of profiles or sheets of about two millimeters to about twelve millimeters in thickness, such as those used in shipbuilding and other metalworking industries.

But even with average thickness components or thick components, the present invention can be used, with the advantages in particular in narrow areas and in critical areas show where a local limitation of Flame refining process is beneficial.

In particular, an application of the present invention is also useful in laser or laser hybrid welded components that cause a different shape change on the component due to their weld geometry than conventionally welded seams. However, it is also possible to use the present invention in the flame straightening of conventional weld seams, since even with conventionally welded seams a change in shape can occur, which requires flame straightening with very close-lying straightening points.

Brief description of the drawings

As already discussed above, there are various possibilities for embodying and developing the teaching of the present invention in an advantageous manner. For this purpose, reference is made on the one hand to the claims subordinate to claim 1 and claim 8, on the other hand, further embodiments, features and advantages of the present invention, inter alia, with reference to the by Fig. 2 illustrated embodiment explained in more detail.

It shows:

• Fig. 1 in a schematic representation of various embodiments of conventional Flame straightening devices in the manner of a flame or Eindüsenbrenners, a multi-flame burner, a switchable three-nozzle burner and a special burner; and
• Fig. 2 a schematic representation of an embodiment of a device for flame straightening, in particular for a multi-nozzle burner, for example for a two-nozzle burner according to the present invention.

Same or similar embodiments, elements or features are in Fig. 1 and in Fig. 2 provided with identical reference numerals.

Best way to carry out the present invention

The principle of flame straightening or Flammrichtbrennens based on the fact that the component or workpiece B is targeted locally heated to the plastic area. This occurs due to impaired thermal expansion a permanent compression. During cooling, there is a shortening in the component or workpiece B, which leads to an intended or desired change in shape.

In particular, narrow areas of the component B are heated to Flammrichttemperatur to cause a targeted upsetting of the heated area of the component B. As a result, the workpiece B, the distortion, warping and / or bending, be brought back into its original shape quickly and gently.

In Fig. 2 FIG. 12 is an exemplary embodiment of a two-nozzle device for flame-straightening, that is to say for a two-nozzle flame-jet burner 100 according to the present invention.

This straightening burner or flame straightening burner 100 can be advantageously used for eliminating angular distortion and for straightening sheet metal structures as well as shipboard skins and is characterized in that the two nozzles 10, 20 are arranged such that the distance between these nozzles 10, 20 at the gas outlet is lower than conventional Flammrichtbrennern.

In this case, the smallest distance of the two nozzles 10, 20 defined at the gas outlet location, that is to say at the nozzle outlet or nozzle end, is reduced in comparison to conventional multi-nozzle burners such that the distance d between the two flames F1 and F2 relative to one another at the pointing points P1 or P2 (= respective impact points the flame on the surface S of the workpiece B) has values in the range of about ten millimeters to about 25 millimeters, preferably in the range of about fifteen millimeters to about 23 millimeters. In exemplary embodiment according to Fig. 2 the value for the distance d is about 20 millimeters.

Due to the reduction in the distance d when using the nozzle according to the invention over conventional flame direction burners, in which the distance is about 30 mm and more, very close-set directing points are machined. The distance of the directing points results from previous work steps in the production and processing of the component or components. Thus, for example, when welding profiles on sheets, ie when a sheet is placed perpendicular to a second, depending on the welding process different points of reference. If the profile is attached by a welding process in which the heat input associated with the welding is very narrow and deep (as is the case for example in laser and laser hybrid welding), the weld metal penetrates very deep in the weld and after solidification it is more or less between sheet metal and profile. Since the profile is welded from both sides and the respective directional point is coupled with the weld, the directional points are in this case very close together. However, if the welding process is carried out in such a way that the solidified weld metal fills the angle between the profile and the sheet metal to a large extent, two less close-fitting points are created. If the straightening points are now to be machined in one work step, the multi-nozzle straightening torch according to the invention is necessary for the tightly aligned straightening points, since in a conventional straightening torch the nozzles can not be mounted correspondingly close to one another. The processing of the reference point is carried out here advantageously using the method of heat screed.

In order to prevent excessive mutual heating of the two nozzles 10, 20, these nozzles 10, 20 according to the basis Fig. 2 illustrated embodiment is not parallel to each other, but arranged at an angle to each other, namely at an angle w of from about one degree to about sixty degrees, preferably from about three degrees to about thirty degrees, more preferably from about five degrees to about fifteen degrees, diverging in the flow direction; In particular, an arrangement is recommended with an angle w of about ten degrees, the angle w by definition of the oriented in the direction of the respective flame F1 and F2 symmetry axes A1 and A2 of the two nozzles 10 and 20, in particular of the respective extensions of this Symmetryeachsen A1 and A2 of the two nozzles 10 and 20, is included as Fig. 2 removable.

Accordingly, the angle included by the direction of each flame F1 or F2 with the surface normal N of the workpiece B is about 0.5w (see FIG. Fig. 2 ), that is about half of that angle, the symmetry axes A1 and A2 of the two nozzles 10, 20 include each other.

Such a V-shaped arrangement of the nozzles 10, 20 is particularly suitable for flame straightening thin-walled sheets or thin-walled profiles, for example in shipbuilding. The heating of the nozzles 10, 20 is thus minimized by the V-position, which leads to an extension of the life of the nozzles 10, 20.

In the two-nozzle flame burner 100 according to Fig. 2 the nozzles 10, 20 are arranged on a transverse strut-like gas distribution pipe 34. This gas distribution pipe 34 is associated with a holder 30 which can be placed on the surface S of the workpiece B and by means of wheels or rollers 32 on this surface S of the workpiece B is movable. This type of arrangement of the nozzles 10, 20 allows a cost effective and effective elimination of changes in shape, which are close to each other on the component B, for example in the region of a weld.

In addition to the arrangement of the nozzle according to the invention there is also a further arrangement possibility, in which the nozzles have a sufficient distance from each other but an angular arrangement is not necessary but the usual parallel arrangement can be selected. This is achieved when the nozzles are arranged so that the processing of adjacent alignment points takes place in succession. Thus, it is possible, for example, to attach two nozzles diagonally on the holder, so that first a reference point and this point of reference opposite reference point is processed a short time later. With such Arrangement, it is also possible to edit dense point of reference (albeit offset in time) without the nozzles heat each other. However, such an arrangement is disadvantageous at corners and edges compared to the arrangement according to the invention, since the subsequent flame can not follow into the corner or edge. Should also be directed in the corners and edges, here a conversion of the straightening burner is necessary.

For the success of the flame-setting process, the performance of the fuel gas, in particular acetylene, is of particular importance. The very high temperature of the flame F1, F2, combined with the high heat output of the acetylene-oxygen flame F1, F2, gives a maximum straightening effect and ensures a fast and precise setting of the flame-rectifying figures. However, the advantages of the invention are shown for all fuel gases, since the inventive advantage of the machinability of the dense gauge points adjusts for all fuel gases. By the variable fuel gas-oxygen flame F1, F2 any desired heat supply can be adjusted, so that an optimal and economical treatment of the workpiece B is possible. Different fuel gases are mentioned, for example, in the standard EN ISO 5172, although the list is not exhaustive there. Compressed air can also be used as combustion partner instead of oxygen. The size of the burner in turn is to be selected depending on the type of material B and / or the thickness of the material B.

LIST OF REFERENCE NUMBERS

100

Device for flame straightening or flame straightening device, in particular straightening burner, for example, two-nozzle flame direction burner

10

first nozzle

20

second nozzle

30

Holder, in particular mobile holder

32

Wheel or roller

34

Gas distribution pipe, in particular transverse strut-like gas distribution pipe

A1

first axis of symmetry, in particular symmetry axis of the first nozzle 10

A2

second axis of symmetry, in particular the axis of symmetry of the second nozzle 20

B

Component or material or workpiece

d

Distance of the flame F1 of the first nozzle 10 to the flame F2 of the second nozzle 20th

F1

Flame, in particular fuel gas-oxygen flame, for example, acetylene-oxygen flame, the first nozzle 10th

F2

Flame, in particular fuel gas-oxygen flame, for example, acetylene-oxygen flame, the second nozzle 20th

N

Normal to the surface S of the component or material or workpiece B

P1

first point of reference, in particular impact point of the first flame F1 on the component or material or workpiece B.

P2

second directing point, in particular impact point of the second flame F2 on the component or material or workpiece B.

S

Surface of the component or material or workpiece B

w

Angle between nozzles 10, 20, in particular between symmetry axes A1 and A2 of the nozzles 10 and 20, for example between respective extensions of the axes of symmetry A1 and A2 of the nozzles 10 and 20, respectively

Claims (10)

For processing at least one component or workpiece (B) provided device (100) for flame straightening, in particular Mehrdüsenrichtbrenner, with at least two nozzles (10, 20),
characterized,
in that at least two of the nozzles (10, 20) are arranged at a non-vanishing angle (w) relative to each other. Apparatus according to claim 1, characterized in that the nozzles (10, 20) are arranged diverging in the flow direction. Apparatus according to claim 1 or 2, characterized in that the angle (w) is one degree to sixty degrees, preferably three degrees to thirty degrees, more preferably five degrees to fifteen degrees. Device according to at least one of claims 1 to 3, characterized in that the nozzles (10, 20) are arranged so that the distance (d) of the flame (F1), in particular the fuel gas-oxygen flame, for example the acetylene Oxygen flame, the first nozzle (10) to the flame (F2), in particular the fuel gas-oxygen flame, for example, the acetylene-oxygen flame, the second nozzle (20) at the respective reference point (P1 or P2) values in Range of ten millimeters to 25 millimeters, preferably in the range of fifteen millimeters to 23 millimeters. Device according to at least one of claims 1 to 4, characterized in that the nozzles (10, 20) are arranged on a, in particular transverse strut-like, gas distribution pipe (34). Device according to claim 5, characterized in that - That the gas distribution pipe (34) is associated with a holder (30) and - That the holder (30) on the surface (S) of the component or workpiece (B) can be placed and / or on the surface (S) of the component or workpiece (B) is movable. Device according to at least one of claims 1 to 6, characterized in that the flame (F1, F2) is an acetylene-oxygen flame. Method for flame straightening, characterized by the use of at least one device (100) according to at least one of claims 1 to 7. Use of at least one device (100) according to at least one of claims 1 to 7 in the flame straightening thin-walled sheets or thin-walled profiles, in particular with a thickness of about two millimeters to about twelve millimeters. Use of at least one device (100) according to at least one of claims 1 to 7 in laser-welded or laser-hybrid welded components or workpieces (B).

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