WO2017129678A2

WO2017129678A2 - Device and method for controlled cooling and heating of metallic workpieces in the temperature field during welding, soldering or thermal separation, during deposition welding and during partial hardening

Info

Publication number: WO2017129678A2
Application number: PCT/EP2017/051641
Authority: WO
Inventors: Bernd Ludewig
Original assignee: Bernd Ludewig
Priority date: 2016-01-26
Filing date: 2017-01-26
Publication date: 2017-08-03
Also published as: WO2017129678A3

Abstract

The invention relates to a device and a method which is carried out by means of the device, for the controlled cooling and heating of metallic workpieces I, II (8, 9) in the temperature field (14) during welding, thermal separating, soldering, deposition welding or partial hardening. As a result of the design of a device with a construction which essentially follows the outer contours of a burner (1), a thermal burning, plasma or laser cutting apparatus or a soldering apparatus, said device being firmly connected to a housing and the housing comprising annularly arranged cooling gas supply lines (3) with cooling gas outlets (4), it is possible to successively or also simultaneously cool and/or heat the surface area of the temperature field (14), in the action area of the temperature field (14) on one or more workpieces I, II (8, 9) during the active working and progression of a modified tool. The device implements an open method for cooling and heating the tool(s) which are to be machined I, II, (8, 9). The respective optimum cooling rate specific to the material and method is controlled, in addition to the flow rate, particularly by the temperature of the cooling gas. The cryogenic gas provided for cooling the temperature field is also used in the the liquid and gaseous portions of the mixture.

Description

Device and method for controlled cooling and heating of metallic workpieces in the temperature field during welding, soldering or thermal cutting, during build-up welding and during partial hardening

The invention relates to a device and a method which is carried out by means of the device for a controlled cooling or heating of metallic workpieces in the temperature field, welding and soldering, in particular arc or laser soldering, the thermal separation, in particular combustion, plasma or Laser cutting, hardfacing or partial hardening, in particular laser hardening, induction hardening.

In this case, it is possible, by the formation of a substantially a burner, a thermal flame cutting apparatus or a soldering apparatus in the outer mold constructed following inventive device that is firmly connected to him and contains annularly arranged cooling gas feeds with Kühlgasaustritten that in the field of training the temperature field - acting on one or more workpieces - already during the active welding / brazing / thermal cutting / surfacing or partial hardening of the aforementioned modified tool, areas of the temperature field can be cooled and / or heated sequentially or simultaneously. In this case, the device realizes an open method for cooling and / or heating one or more workpieces to be machined.

According to the known state of the art, a large number of solutions have become known which prefer closed systems (with, for example, recirculation of the coolant) or even open systems to cooling, which in some cases require a great deal of constructional effort and therefore hardly any Manual work processes are suitable.

By way of example, the prior art will be discussed below.

Thus, according to DE 3936205 C2 an arc welding lance is known, which is equipped with a cooling and blowing device. It is to be achieved that the welding zone is blown open and cooled in a surface widening the burner, in particular by welding fumes. A controlled preheating or reheating and a simultaneous cooling is not provided. According to DE 102013022056 A1, an apparatus and a method for conditioning a welding and cutting process are presented. A tempered gas stream is proposed here as a cold or hot gas stream for arc welding or autogenous burning. It is intended to keep the temperature field stable and to influence workpiece parameters.

DE 19704142 A1 discloses a cooling method for an inert gas welding device and an inert gas welding device with a cooling device. The two parts of a gas stream are used once for cooling and secondly as a protective gas stream. The structure requires a considerable amount of equipment and can therefore only be used for robots.

Finally, it will be discussed on US 4057332 A. Here, annularly arranged openings enclose a lens of a laser. There are inlets and outlets for liquid cooling.

To overcome the disadvantages and to improve the state of the art, it is therefore necessary to search for a practicable and simply designed solution.

It is therefore an object of the invention to propose a device and a feasible with her method for controlled cooling and / or heating of metallic workpieces, then permanently recorded and evaluated temperatures in the temperature field of a thermal machining tool, during the working progress thereof, a workpiece surface either sequentially or also locally targeted cooled and / or preheated at the same time. This should make it possible to avoid stresses, distortions and / or changes in the structure of the workpiece material in the area of a solder joint, a weld, a thermal parting line or a laser hardening.

The object of the invention is achieved as follows, wherein the basic features of the device in claim 1 and those of the method in claim 8 are given.

Further features embodying the invention follow in claims 2 to 7 and 9 to 13. The invention relates to an apparatus as an open system for controlled cooling and / or heating of metallic workpieces in the temperature field during welding, soldering, thermal cutting, build-up welding or partial hardening, wherein a housing with a burner, such as a welding torch, firmly connected is, which includes annularly positioned and axially parallel to the central axis of the burner extending Kühlgaszuführungen whose Kühlgasaustritte involve a larger area than that of the protective gas nozzle and, the cooling gas outlets are seen in the direction of the workpieces, arranged in front of the outlet opening of the protective gas nozzle of the burner.

Such a device has the advantage that no complicated and specially designed to avoid environmental influences designed closed housing in the field of temperature field, the burner itself does not have to be consuming provided in its interior with cooling channels, the work process can be better controlled and the device in its simple design also for burners of hand welding and thermal cutting can be harnessed.

In one embodiment of the invention it is provided that the cooling gas supply each have a heating coil. Thereby, each of the cooling gas supply lines can fulfill the function of preheating or cooling. By means of a computer-aided detection and evaluation of the temperature conditions in the temperature field, the cooling gas supply can thereby be selectively switched to at least one, in particular metallic, workpiece during thermal separation, build-up welding or partial hardening or two of them in a welded joint / solder joint at the periphery of the temperature field preheat and / or cool.

According to the invention, the cooling gas supply lines are located in a housing which is fixedly connected to the burner by means of ribs extending axially parallel to the central axis of the burner. The housing is adapted to the shape of the burner and designed so that due to its lightweight design, the burner can be used in addition to its use in welding robots for welding by hand or manual thermal cutting application.

Furthermore, the distance between the ribs is chosen so that at least one cooling gas supply is placed between them. With the saving of ribs, which are not necessarily required for the stability of the construction of the housing according to the invention, a weight reduction of the same can be achieved, which is especially important for use in manual processing methods. The cooling gas supply, which are enclosed by the housing of the device according to the invention, have a circular or polygonal cross-section. The decision is made on the basis of available space, especially when using the burner in welding robots.

In a variant of the aforementioned device, the cooling gas supply lines are visibly fixed by means of one or more fastening elements on the outer surface of the burner, parallel to the central axis thereof.

This results in a reduction in the weight of the burner and it can be performed during servicing uncomplicated maintenance.

It is also advantageous in this weight-reduced embodiment that the cooling gas feeds in the direction of the cooling gas outlet, as shown in the embodiment of Figure 4, have an away from the burner outwardly pivotable tail.

Thus, the temperature field can be variably increased or decreased in welding, brazing, thermal cutting, build-up welding, and partial hardening with respect to reaching an area for preheating or cooling.

With the device, a method for a controlled cooling and / or heating of metallic workpieces in the temperature field during welding, soldering, thermal cutting, build-up welding or partial hardening feasible by a sensory detection of the temperature field, carried out continuously by means of at least one pyrometer and then via Kühlgaszuführungen with their cooling gas outlets successively or simultaneously a cooling and / or preheating of workpieces I and / or II in the range of the temperature field is performed.

Such a measure has the advantage that the heat input into the material of the workpieces is as small as possible in terms of time and location, so that even thin-walled parts can be manufactured almost without delay and the preheating and cooling so effectively, that is so localized As possible, so that the structure of the or the workpieces in the temperature field does not change unintentionally, that is possibly hardened.

In a further embodiment of the method, the cooling gas feeds are acted upon in such a way that a weld or soldering or a joint of a thermal separation process, a hardfacing or a hardening track on individual or sequential to be activated cooling gas supply with their cooling gas outlets of a in the Cooling gas supply heating coil, preheated before this and next to and behind the weld / soldering or joint is cooled, wherein the build-up welding and partial hardening the cooling in the majority of applications only from the side opposite the side of the build-up welding or laser hardening , he follows.

Thus, a targeted pre- and post-treatment of the material of one or two workpieces directly in the temperature field is already given during a welding / soldering, hardness, or thermal separation process.

In tubular workpieces, the cooling according to the invention can also be done inside, which is a sensible option especially for partial hardening, build-up welding and multi-layer welding.

A separate cooling gas supply also allows the material-optimized delay minimization by the variable cooling capacity of this invention in inductive hardening.

The issues of occupational safety and health, as already provided for in many applications, should be taken into account by adequate gas extraction.

It is further provided that cryogenic gas is used in the mixture of a liquid and gaseous fraction for cooling the temperature field.

This is advantageously in the same direction as a z. For example, in a welding process, protective gas flowing from a protective gas nozzle is introduced into the temperature field. This makes it possible to control the respective material and process-specific optimum cooling rate not only via the flow rate but also via the temperature of the cooling gas.

For preheating can be used for cost reasons, in a further embodiment, air instead of the cryogenic gas.

For a cryogenic gas should preferably be used in welding argon.

In a welding process, when a root pass needs to be welded, a cryogenic forming gas may be supplied to the root by cooling via bath rails which are combined with forming gas nozzles and a main cooling nozzle. Both a cooling on both sides as well as an exclusive cooling of the arc / plasma jet / laser opposite side is possible, which extends the application possibilities of the invention material and process conditions. This procedure can be transferred according to the invention in addition to welding on the brazing, thermal cutting, build-up welding and partial hardening.

Finally, according to the method is provided that, when welding light metal or light metal alloys, depending on the welding speed, a preheating with hot air of about 200 ° C to 600 ° C takes place. Wherever it makes more economic sense and process technology is allowed this can also be conventional z. B. done by induction or infrared heating.

It is also conceivable, temperature shock sensitive materials such. As alumina ceramic, according to the method during welding preheat, weld and reheat. This avoids the risk of mechanical stress. A heat-insulating base is to be used here.

With the proposed device and the process that can be implemented with it, in the implementation of thermal bonding and separation processes of welding technology, the order soldering and the partial hardening in the machining of metals, their alloys and other weldable composite materials, the design effort for producing a suitable solution can be reduced while minimizing manufacturing costs.

The invention will be explained in more detail with reference to embodiments. Reference is made to FIGS. 1 to 7.

1 perspective view of a burner with temperature field control, FIG. 2 top view of the burner from below, FIG.

FIG. 3 Inventive measurement of the workpiece temperature in schematic representation,

FIG. 4 side view of the cooling gas supply lines of the burner,

5 shows section A-A at the burner with cooling gas supply lines according to FIG. 4, FIG.

Figure 6, 6b front and side view of the burner of Figure 4 in combination with

Formiergasdüsen and a main cooling nozzle as well Figure 7 Top view of the Formiergasdüsen and the central main cooling nozzle.

Figure 8 Perspective view of the cooling gas flow in tubular workpieces

- The cooling gas is supplied from the chuck ago.

Figure 9 Perspective view of the cooling gas guide in tubular workpieces - wherein the cooling gas is fed to the chuck.

According to FIG. 1, it can be seen that a housing 6 is arranged on the burner 1 with the cooling gas supply lines 3 which are annularly enclosed by it. In this case, there is a plurality of cooling gas outlets 4 near the beginning of the formed in the form of a cone shielding gas nozzle 5. The cooling gas supply 3 are separated by ribs 7 from each other, wherein the ribs 7 and the housing 6 connect to the burner 1.

Figure 2 shows a view of the inventively constructed burner 1 as a plan view from below. The cooling gas feeds 3 have a circular cross-section, which, however, can deviate therefrom according to design requirements which dictate the design of the burner 1 for manual or automated welding.

In FIG. 3, in principle, the measurement according to the invention of the workpiece temperature during welding is shown. The on the workpieces Ι, ΙΙ, 8, 9 resulting temperature field 14 probing pyrometer 1 1, 12 transmit their data to a computer-aided temperature field monitoring, which causes the ring 6 enclosed by the housing 6 Kühlgaszuführungen 3 depending on the desired cooling capacity by different admixture of gaseous and / or liquid cooling gas and are controlled in terms of the cooling location so that the temperature field 14 is preheated and / or cooled in succession or simultaneously during the feed of the burner 1. In this case, the cooling capacity of each cooling gas supply 3 can be set separately. The gas supply of each cooling gas supply 3 can also be switched off separately. As the cooling gas, for example, the noble gas argon is used, and hot air can also be used during preheating.

In a specific embodiment, the cooling gas supply 3.1 is either switched off during operation or used for preheating, the cooling gas supply 3.2 is used for cooling or preheating and the cooling gas supply 3.3 is often switched off during welding, during soldering, however, this is used for cooling. FIG. 4 shows how, in a variant of the device, the cooling gas supply lines 3 are arranged in a circle around the burner 1 and fastened to it by means of a plurality of fastening elements 17.

The section A-A according to FIG. 5 indicates that the cooling gas supply lines 3 are arranged equidistant from each other, distributed in a ring around the burner 1.

The end pieces 16 of the cooling gas ducts 3 are designed to be pivotable in this embodiment and, for example, can be pivoted away from the burner 1, whereby the area to be cooled or the area to be heated changes.

According to Figure 6a and 6b is shown in principle in front and side view, as several Formiergasdüsen 18, for example, in automated root welding below the root 19 are positioned and thus in controllable coordination with the mounted on the burner 1 cooling gas 3 a two-sided cooling of the workpieces to be joined I.II, 8.9 is accomplished.

It can be seen in FIG. 7 how, in principle, a plurality of annularly arranged forming gas nozzles 18 and a centrally arranged main cooling nozzle 20 are provided below the welded root 19. The main cooling nozzle 20 comes only after closing the root 19 used.

In the figures 8 and 9 is shown in principle how the cooling gas guide is preferably designed for open tubular workpieces when the cooling should be done from the inside.

The advantages of the invention are summarized in:

Suitability for a variety of thermal welding, cutting, soldering, hardfacing and partial hardening tools.

Already during the thermal welding, cutting, soldering, build-up welding or partial hardening, preheating, cooling and possibly reheating are possible. Avoidance of changes in the material structure in the area close to the weld seam and on the flanks of a parting line and no residues of a coolant requiring disposal. Prevention of hardness and hot cracks, smaller temperature field with smaller heat affected zone, shortening of welding time in multi-layer welds, increase of weld quality (controlled cooling).

Significant reduction in temperature-induced workpiece distortion and saving on expensive and time-consuming clamping and relining with copper.

Prevention of cold cracks by reducing the temperature gradient. (Preheating, possibly also reheating).

In multi-layer welds shortening of the welding time, since after welding the root seam and the first cover seam, before welding the next intermediate layer no longer has to be maintained until the seam has cooled down. Thus, with duplex steels, the correct interpass temperature is currently only reached after approx. 15 minutes. The cooling of the solder joints improves the metal structure of the solder joint and their shock-like cooling is often increased their strength by the formation of a fine-grained structure.

Heat input to the kerf limiting material and its concomitant consequences such as distortion and tension are reduced, which on the one hand improves the quality and on the other hand, a cost-effective method such. As plasma cutting instead of laser cutting ensure the required quality and save on manufacturing costs.

LIST OF REFERENCE NUMBERS

1 burner

2 welding electrode

3, 3.1, cooling gas supply

3.2, 3.3 Coolant gas supply

4 cooling gas outlet

5 shielding gas nozzle

6 housing

7 rib

8 workpiece I

9 workpiece II

10 lasers / burners

1 1 pyrometer

12 pyrometers

13 wire

14 temperature field

15 heating coil (not shown in cooling gas supply 3 integrated)

16 end piece, swiveling

17 fastening element

18 forming gas nozzles

19 root

20 main cooling nozzle

21 Werkstückeinspannung, in the embodiment with three-jaw chuck

Claims

claims

1. Device as an open system for a controlled heating and / or cooling of metallic workpieces Ι, ΙΙ (8,9) in a temperature field (14) during welding, thermal cutting, soldering, build-up welding or partial hardening, characterized in that a housing ( 6) is fixedly connected to a burner (1) which annularly positioned inside the housing and axially parallel to the central axis of the burner (1) extending Kühlgaszuführungen (3) whose cooling gas outlets (4) include a larger area than the protective gas nozzle (5) and , which are arranged in the direction of the workpieces (8, 9) to be machined in front of the outlet opening of the protective gas nozzle (5) of the burner (1).

2. Apparatus according to claim 1, characterized in that the cooling gas supply lines (3) each have a heating coil (15).

3. Apparatus according to claim 1 and 2, characterized in that the housing (6) via axially parallel to the central axis of the burner (1) extending ribs (7) with the burner (1) is firmly connected.

4. Device according to one of claims 1 to 3, characterized in that the distance between the ribs (7) is selected so that between these at least one cooling gas supply (3) is arranged.

5. Device according to one of the preceding claims 1 to 4, characterized in that the cooling gas supply lines (3) have a circular or a polygonal cross-section.

6. Device according to one of the preceding claims 1 to 5, characterized in that the cooling gas supply lines (3) are fixedly mounted by means of one or more fastening elements (17) on the outer surface of the burner (1), parallel to the central axis thereof.

7. Apparatus according to claim 6, characterized in that the cooling gas supply lines (3) in the direction of the cooling gas outlet (4) have a pivotable end piece (16).

8. Method for a controlled heating and / or cooling of metallic workpieces I, II (8, 9) in a temperature field (14) during welding, thermal cutting, soldering, build-up welding or partial hardening, characterized in that a sensory detection of the temperature field ( 14) by means of at least one pyrometer (1 1, 12) made continuously and then via Kühlgaszuführungen (3) with their cooling gas outlets (4) successively or simultaneously preheating and cooling of the workpieces I, II (8, 9) in the range of the temperature field (14 ) is carried out.

9. The method according to claim 8, characterized in that the cooling gas supply lines (3) are acted upon in such a way that a weld / soldering or a joint (21) of a welding, soldering or a thermal separation process via individual or in a sequence to be activated Kühlgaszuführungen (3) with its cooling gas outlets (4) preheated by a heating coil located in the cooling gas supply (15) and next to and behind the same, the weld or joint (21) is cooled.

10. The method according to claim 8 or 9, characterized in that for cooling the temperature field (14) cryogenic gases are used in the mixture of a liquid and gaseous portion or air.

1 1. A method according to claim 10, characterized in that argon is used as the cryogenic gas in welding.

12. The method according to any one of the preceding claims 8 to 1 1, characterized in that when cooling a root (19) in a thermal welding process, a forming gas via Badsicherungsschienen which are combined with Formiergasdüsen (18) and a main cooling nozzle (20) is supplied ,

13. The method according to any one of the preceding claims 8 to 12, characterized in that, when welding light metal or alloys or of ceramic materials, depending on the welding speed, a preheating with hot air of about 200 ° C to 600 ° C.

14. The method according to any one of claims 8 to 13, characterized in that in the treatment of tubular workpieces, the cooling takes place from the inside and / or from the outside.