DE8211393U1 - Welding gun - Google Patents

Description

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Dlp '.- Ing Dr.-Ing. HEINZ NICKELS · Dlpl.-Phys. LORENZ HÄNEWINKEL PATENT LAWYERS Detmolder Strasse 26 - 4800 Bielefeld 1

G 82 11 393.9 «R 32/59)

Carbon dioxide works CG. Rommenhöller GmbH, Rommenhöller Strasse 32, 3490 Bad Driburg-Herste

Welding gun

The innovation relates to a welding gun for carrying out a protective gas arc welding process, in which two gases (an inert gas and an active gas) are separated, but fed to the welding point at the same time whose nozzle head is a central guide for a consumable welding wire (electrode), a this guide arranged, an annular channel for the inert gas as a central flow forming, inner gas pipe and one arranged around this inner gas pipe and forming an annular channel for the active gas as a sheath flow Has outer gas pipe.

On the basis of various welding tasks in the field of gas-shielded arc welding processes, commercial welding guns constructed according to the type mentioned at the beginning, gas routing and flow criteria examined under thermal load, i.e. during the welding process. That led to the realization that this is Form burner- and workpiece position-dependent shielding gas flows that vary in direction and flow velocity change very much. Especially with the two / gas

welding, these features lead to the leakage of the centrally guided inert gas flow and to a diversion of the arc from the desired seam position. There are uneven seams or undercuts the undesirable consequences. In addition, there is a strong directional drift of the protective gas flow Suction is used and thus ambient atmosphere is brought to the welding point, which the known, negative influences on the weld pool. Compensation options consist of that the amounts of protective gas are increased, but this only partially leads to success and what higher costs for the protective gas component.

The task of the innovation is therefore to improve a welding gun with a nozzle head so that it when using different shielding gases in a mixture, separately or separately, leading to the welded parts Assignment, as with two-gas welding, including the weld pool and the solidification area Protective gas zone that forms in the event of unfavorable or changing positioning of the welding gun with mechanical or hand-held welding in a given amount, largely stable and flow-compensated Remains formed over the entire time range of the welding process.

This object is achieved according to the invention by the characterizing features of claim 1, the in The design features listed in the subclaims represent advantageous developments of the solution to the problem.

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The subject of the innovation extends not only to the features of the individual claims, but also on their combination.

The welding gun according to the invention has created an extremely favorable C isstromführung for the inert and the active gas through simple measures / namely the arrangement of bores in the gas pipes, whereby through this. Guidance, even with unfavorable welding gun guidance or positioning, a protective discharge zone including the weld pool and the solidification area is created, in which the arc is kept stable and cannot break out, since the gas flow guides the inert gas to the welding wire melting point in a laminar manner without the active gas flow accompanying it thermal load caused by turbulence or deflections of the flow if the welding gun (the torch) is not positioned correctly from the arc area, which would lead to the early penetration of the active gas into the arc attachment point and result in spatter formation.

As a result of the separate (unmixed) two gas supply, in particular argon-CO 2 supply, in addition to the more targeted action of both gas components, there is the essential advantage that the proportion of CO 2 can be greatly increased. In a favorable manner, only a proportion of argon of about 15 to 20% is required, so that the costs for the protective gases are also greatly reduced _{due to the cheaper CO 2.}

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Based on the drawings, an example is shown in accordance with the innovation explained in more detail below. It shows:

1 shows a vertical section through a nozzle head of a welding gun with two nested / Gas pipes forming annular channels and radial gas flow openings arranged therein;

FIG. 2 shows a cross section through the nozzle head according to FIG

Section line A-B in FIG. 1 with radial gas throughflow openings in the inner gas tube;

3 shows a cross section through the nozzle head according to the section line C-D in FIG. 1 with radial gas throughflow openings in the outer gas pipe;

Fig. 4 is a front view of the nozzle head seen in the longitudinal direction of the weld to be created, in partial cut, with two at an angle to each other and connected by a fillet weld Workpieces, and with gas flows indicated by the arrows.

The welding gun according to the innovation for carrying out a gas-shielded arc welding process has a nozzle head 1 with which two gases are fed separately, but simultaneously to the welding point 2, and “was an inert gas as the middle flow 3 and an active gas as the sheath flow 4. The inert gas is a gas that lie within the element group EIGHT, such as argon, helium or the like, and in the case of the active gas around CO ₂ .

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The nozzle head 1 shows a central guide 5, such as channel, Tube or the like for a melting welding wire 6 (electrode). Around this guide 5 is an inner one Gas pipe 7 is arranged, which with the guide 5 forms an annular channel 8 for the inert gas medium flow 3. An outer gas pipe 9 is arranged around the inner gas pipe 7 and forms an annular channel with the inner gas pipe 7 10 results for the active gas jacket stream 4.

The electrode guide 5 and the two gas pipes 7, 9 are arranged coaxially to one another and the two gas pipes 7, 9 close at the gas outlet end face of the nozzle head 1 - the gas outlet 11 - flush (in a direction transverse, preferably at right angles to the gas flow direction Level).

A feed insert 12 for the inert gas is screwed into the inner gas pipe 7, one of which extends in the direction of gas flow Continuing, cylindrical extension 13, which with the inner gas pipe 7 at a distance from the gas outlet 11 forms part of the annular channel 8. Through the insert 12 and the approach 13, the inert gas is supplied, which from shell-side openings 14 of the extension 13 can flow radially into the annular channel.

Within the inner gas tube 7, a contact tube tip 15 is releasably attached to the cylindrical extension 13, which rests under the end face of the extension 13 and is screwed into the extension 13 with a threaded pin 15a. These Contact tube tip 15 is cylindrical following attachment 13 formed and with attachment surfaces 15b for a tool

equipped for screwing in and out and then goes to the free front end in a cone 16, which is in Distance to gas outlet 11 ends in a ball 17.

In this contact tube tip 15 and the approach 13 as well Insert 12 is set as an electrode guide 5 a hole.

At least one of the two gas pipes 7 or 9 is in the Ab- '; stood for the front gas outlet 11 with several radial Gas flow openings 18, 19 equipped. It is preferred to keep the outer gas pipe 9 with these Gas flow openings 18 to be provided in the tube each at the same distance - that is, at the same height - are arranged from the gas outlet 11, the inner one Gas pipe 7 does not necessarily have to be provided with gas passage openings 19; this depends on the set welding task.

Preferably, both gas pipes are; 7, 9 - as in ' shown in the drawings - with radial gas flow openings 18, 19, these openings 18, 19 are arranged in the two tubes 7, 9 at a distance from the gas outlet 11 and at a distance from one another. The gas flow openings 18, 19 are preferably formed by bores.

The radial bores 19 of the inner gas pipe 7 are: either at an angle of 90 ° to the gas flow direction and thus with the pipe's longitudinal direction or at a certain angle against the gas flow direction or in the gas flow direction, this angle X ₁ , X ₂ ( see. Fig. 1) is preferably about 15 ° or more.

The radial bores 18 of the outer gas pipe 9 are also at an angle of 90 ° to the direction of gas flow and thus in the longitudinal direction of the pipe or they are in the gas flow direction at an angle Y set of approx. 15 ° or more (see Flg. 1).

The arrangement of the bores 19 as gas transfer bores of the inner gas pipe 7 are provided in a ratio D.: L ₁ of 1 t 2.5, starting from (\ D ₁ In the range from 7.5 to 9 mm «The holes 18 of the

outer gas pipe 9 as gas pressure compensation bores are in a ratio of D ₂ : L ₂ · 2 t 1, where D _{2 is} in the range from 16 to 19 mm (see Fig. 1).

The size and number of the bores 18, 19 is furthermore given as an area ratio to the GaS exit area. Here, the area ratio F ₁ and F _{2 of} the bores 19 shown in FIG Annular channel 8 ■ 1.2 t 1, starting from four bores 19 with a diameter of 1.5 to 2.5 mm.

ν The area ratio F ₃ and F. of FIG. 3 for

the bores 18 to the annular channel 10 lying in the cutting plane C-D is 2.3 t 1, starting from eight Bores 18 with a diameter of 2.5 to 3.5 mm.

The wall thickness of the inner gas pipe 7 in the end region on the gas outlet side (according to section line CD) is _{1.5 mm to ensure the remaining cross section F 3 of} the longitudinal duct 10, St

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The position measure for the contact tip 15 according to L, according to Piy. 1 iet, starting from D, ~ 7, b up to ¹ J min in a ratio of D _{1 to} L ₃ »3 5 1. .

The design of the contact tube tip 15 for the entire area of application D ₁ : L ₃ in its spherical branch located at a distance from the Caeau inlet 11 was R-sphere = 2.5 mm, that is, R-sphere is in the entire area U ^ (7.5 up to 9 mm) always 2.5 mm. The cone angle 16 is determined according to the area portion F in the cutting plane AB and the resulting diameter of the seat 13, so that the cone angle 16 becomes more acute or obtuse in accordance with this area portion with the R-sphere remaining the same.

As can be seen from Fig. 1, the annular channel 10 of the outer gas pipe 9 runs over the entire length of the nozzle head cylindrical and the inner gas tube 7 is conically narrowed in the region of the contact tube tip cone 17 by it at a distance behind the holes 19 to about the Bores 18 narrows conically in the gas flow direction and then cylindrical up to the gas outlet 11 expires.

When using, for example, CO ₂ as the sheath flow and, for example, argon as the middle flow, the bores 19, which are at 90 ° to the gas flow direction, are a favorable arrangement for the inner gas pipe 7, so that in the event of a gas congestion a corresponding inert gas component can flow over into the active gas component and thus the transition zone 20 according to FIG. 4 is supported.

It is important that the end piece of the outer gas pipe 9 remains designed as a closed ring, the one Form a largely closed gas column in the direction of the weld pool to be covered, even against thermal load can.

From Fig. 4, the flow of the two gases 3, 4 is clearly visible and therein is the gas balance zone with 21, the Transition zone (inert and act! "Gas) with 20, the light bulb) Gene and material transition zone in the inert gas area with 22

and denoted by 23 the gas congestion zone.

The interlocking gas pipes 7,9 and the feed insert 12 and the contact tube tip 15 held thereon are detachably interconnected individual parts that oppose one another can be exchanged (exchanged when worn).

The attachment of the nozzle head 1 to the welding gun is in different ways and according to the respective requirements by screwing, plugging, bayonet lock or the like. Possible.

It is within the scope of the innovation, the holes 18 of the outer Gas pipe 9 and also the bores 19 of the inner gas pipe 7 each at different heights to see ,, that is, each group of bores 18 and / or 19 in the direction of flow of the gases, for example on the pipe circumference, in a zigzag shape has arranged bores 18,19.

It is also part of the innovation, the gas flow openings 18:19 not as holes, but as elongated holes, Make slots or angular breakthroughs.

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There is also the possibility of providing the inner gas tube 7 set back with respect to the outer gas tube 9 on the gas outlet end face 11, this setting back up to a maximum of the contact tube tip ball 17, i.e. by the dimension L ₃ .

In Fig. 4 of the drawing, for example, is the swing exercise a fillet weld 2 on two at an angle to one another Workpieces 24 shown, it being with this

ζ Welding arrangement around the most extreme representation of the gas

management, in which mainly the features of the innovation show their full effect.

The inert gas flow 3 can flow through the bores during the gas build-up which occurs during the welding process 19 partially break it down by adding a small amount of inert gas through the bores 19 in the annular channel 10 of the active gas flow 4 can flow, so that a certain proportion of inert gas is also present in the sheath flow 4, which in particular supports the transition zone 20.

Due to the special management and assignment of the Gasetrö-V me 3,4 and in particular due to the main share of active

g _a s in the zone 23 of the inert gas 3 wire inevitably as a tapered cone (within the range 20) to the weld seam 2 toward formed, in particular as far as formed so that the Drahtabschmelzpunkt 22 remains in the pure Inertgaszone.

The required amount of active gas and the distance from the welding gun to the workpiece 24 leads to the inevitable jam in the welding task shown in FIG. 4

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which is formed as evenly as possible on all sides, i.e. in the transverse and longitudinal directions, the weld seam 2 is to be reduced, with the welding task shown the angled workpieces 24 represent with their side flanks a resistance that the Main shielding gas flow only in the longitudinal direction of the weld seam 2 ie the main part can be reduced in a different way Positioning of the torch or a change in positioning during the welding process in addition, that the gas flow runs either in the welding direction or against or with the welding direction, see above that this creates a main oriented direction. The sheath flow when congestion forms is through the bores 18 degraded on all sides and emerges from these bores 18 in all directions, with This sheath current 4 is then placed evenly over the entire weld 2 as inert gas protection. There the sheath flow 4 also runs in a laminar manner, the inert gas component in the laminar flow also in the event of a build-up Active gas portion transferred, through the bores 19 to an extremely small proportion, which is then in the further course is carried out in a laminar manner and remains in the inner area of the outer active gas area, with flows out and thereby supports the transition zone 20. This creates a largely calm and to Weld seam 2 oriented towards, stable gas zone, so that thereby, in particular, the energy field of the spray arc is largely bundled. and on the geometric center of the The course of the weld seam is kept stable, since otherwise the undesired undercuts would arise when deflected.

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It is also part of the innovation, the welding gun only to be equipped with a pipe 7 or 9, which then has the gas pressure equalization bores 18. In the case of such a single-tube surge, mixed gas or active gas is used. This training of the welding gun represents an independent inventive idea, because by the Bores 18 in the one pipe 7 or 9 the same before partial effect of arc stabilization. - · as arises with the two-barrel pistol.

Claims (18)

Protection claims 1. Welding gun for carrying out an inert gas arc welding process, bsi dem two gases (an inert gas and an active gas) separated, but at the same time to the welding point, the nozzle head a central guide for a consumable welding wire (Electrode) / a arranged around this guide, () an annular channel for the inert gas bil as a middle flow The inner gas pipe and an annular channel for the active gas arranged around this inner gas pipe has as a sheath flow forming outer gas tube, dadurc h characterized that at least the outer gas pipe (9) at a distance from the end-fit gas outlet (11) with several radial Gas throughflow openings (18,19) is provided. 2. Welding gun according to claim 1, characterized in that the gas through-hole openings (18,19) are formed by bores. - 3. Welding gun according to claims 1 and 2, there characterized in that the inner gas pipe (7) with several, on the same plane arranged gas flow openings (19) is provided. 4. Welding gun according to claims 1 and 2, characterized in that the outer gas pipe (9) equipped with several gas flow openings (18) arranged on the same plane is. 5. Welding gun according to claims 1 and 2, characterized in that both Gas pipes (7, 9) are each provided with a plurality of gas through-flow openings (18, 19), the gas through-flow openings (18,19) of both gas pipes (7,9) each on a common, but at a distance in the gas flow direction mutually arranged plane and thereby the gas flow openings (18) of the outer gas pipe (9) at a smaller distance from the gas outlet (11) than the gas throughflow openings (39) of the inner gas pipe (7) are provided. 6. Welding gun according to claims 1 to 5, characterized in that the Gas throughflow openings (38, 19) are at an angle of 90 ° to the gas flow direction. 7. Welding gun according to claim 6, characterized in that the bores (19) of the inner gas pipe (7) are provided at right angles or at an angle CC., X ₂ ) of about · 15 in or against the direction of gas flow. 8 * welding gun according to claim 6, characterized in that that the bores (18) of the outer gas pipe (9) are at right angles or at an angle (Y) of about 15 ° in the gas flow direction. 9. Welding gun according to claims 1 to 7, characterized in that the bores (19) of the inner gas pipe (7) are arranged as gas transfer bores in a ratio of D ₁ : L. = 1: 2.5, starting from D. « 7.5 to 9 mm (Fig. 1). 10. Welding gun according to claims 1 to b and 6, characterized in that the bores (1ö) of the outer gas pipe (9) are arranged as GasdruckausgleJdisbohrungen in a ratio of D- ι L- « ² S ¹ , starting from D ₂ - 16 to 19 now (Fig. 1). 11. Welding gun according to claims 1 to 10, characterized in that the area ratio F-: F _{2 of} the bores (19) to the annular channel (b) ■ is 1.2 t 1, starting from four bores (19) with a diameter of 1.5 to 2.5 mm (Fig. 2), 12. Welding gun according to claims 1 to 10, characterized in that the area ratio F t F _{4 of} the bores (1b) sum of the annular channel (10) ** is 2.3 t 1, based on eight bores with a diameter of 2, 5 to 3.5 mm (Fig. 3). 13. Welding gun according to claims 1 to 12, characterized in that in the inner gas tube (7) a on a feed insert (12) releasably held contact tube tip (15) is arranged, which is with its spherical end at a distance from the Gaaauetritt (11) , with this distance (position dimension) L- starting from D. »7.5 to 9 on in a ratio of D ₁ t L ₃ * 3 1 1 (Fig.1). 14. Welding gun according to claim 13, characterized / that the radius (R) of the contact tip ball (17) for the entire design area D. ι L _{3 is} 2.5 mm (Fig. 1), the cone angle of the contact tip cone (16) after the area _{portion F 1} and the resulting diameter is determined by Cig. 1 and 2). 15. Welding gun according to claims 1 to 14, d a / characterized in that the Annular channel (10) of the outer gas pipe (9) is cylindrical over its entire length and that inner gas pipe (7) at a distance behind its bores (19) in the direction of gas flow up to the bores (18) of the outer gas pipe (9) is tapered and then runs out cylindrically to the gas outlet (11) (Fig. 1). 16. Welding gun according to claims 1 to 15, characterized / that the gas pipes (7/9) and the insert (12) with contact tube tip (15) detachably (exchangeably) connected to one another (and the nozzle head (1) by means of a plug-in, screw connection od. The like. Can be releasably fixed on the welding gun. 17. Welding gun according to claims 1 to 16 / characterized / that the wall thickness of the inner gas pipe (7) in the gas outlet end region to ensure the permanent annular channel cross-section (F ₃ ) is 1/5 mm. 18. Welding gun according to claims 1, 2, β to 10 / characterized / that the bores (18,19) of each of the two tubes (7,9) Arranged at different heights on the pipe circumference, preferably in a zigzag shape are* 19, welding gun, in particular according to claims 1, 2 and 8, thereby marked () net that the same is only possible with a radial gas having flow openings (18) and with mixed gas or active gas working gas pipe (9) equipped 1st.