AT504409B1 - PROTECTIVE RING FOR A WATER STEAM PLASMA BURNER - Google Patents

Description

(19) Austrian Patent Office (10) AT504 409B1 2008-09-15 (12) Pate (21) Application number: A 1754/2006 (22) Date of filing: 2005-09-09 (43) Published: 2008-09-15 ntschrift 51) Int.CI.8: B23K 10100 (2006.01) (62)

Excretion from A 1483/05 (73)

Applicant: (56)

References: US 5856647A FRONIUS INTERNATIONAL GMBH A-4643 PETTENBACH (AT)

Fig.ll

AT504 409B1 2008-09-15

(54) PROTECTION RING FOR A WATER STEAM PLASM BURNER (57) The invention relates to a protective ring (41) for a steam plasma burner (6) which protects the components of the steam plasma burner (6) against thermal effects and isolates current-carrying components, wherein at least one end face (58) a fixing device (59) for detachable mounting on a protective cap (23) is arranged, and a recess (56) is provided which is formed during assembly for receiving and enclosing a nozzle (21). In order to be able to carry out a change of the nozzle of a steam plasma burner in the simplest possible way, the fastening devices (59) for receiving in corresponding recesses (47) of the protective cap (23) and for locking in the recesses (47) formed by a rotational movement. DVR 0078018 2 AT 504 409 B1

The invention relates to a protective ring for a water vapor plasma burner, which protects the components of the steam plasma burner from thermal effects and isolated current-carrying components, wherein at least one fastening device for releasable mounting to a protective cap is arranged on one end face and a recess is provided, which in the assembly for receiving and enclosure of a nozzle is formed.

Devices for changing a nozzle of a plasma welding torch are known from the prior art, wherein the nozzle must be released by a rotational movement of the plasma welding torch, as is known from AT 411 972 B. Here it is described that the nozzle with a screw, that is a thread, is attached to the plasma welding torch. To change the nozzle you must first remove the gas nozzle, then you can unscrew the nozzle. This is done with a suitable tool, since the nozzle is heated accordingly after a welding or cutting process.

The disadvantage here is that two steps are necessary for a change of the nozzle, as previously the gas nozzle must be removed. Likewise, accordingly protective measures are to be taken, since in particular the parts are heated around the nozzle of the plasma welding torch after a welding or cutting process.

US 5,856,647 A describes a protective cap for a plasma torch of the subject type, wherein the disassembly of the nozzle in addition to the removal of the protective cap but also the removal of another sleeve, which is mounted by means of a thread on the burner, requires.

The object of the invention is to carry out a change of the nozzle in the simplest possible way, the disadvantages of the prior art can be avoided.

The object of the invention is achieved by an above-mentioned guard ring, wherein the fastening devices are designed for receiving in corresponding recesses of the protective cap and for engaging in the recesses by a rotational movement. It is advantageous here that the nozzle, in particular the projection, is enclosed, whereby the protective effect against contamination is increased. Thus, an effective protection of the driver area, the corresponding recess in the protective cap and the mounting area is ensured. By the measure that the guard ring of the protective cap is solvable, this can on the one hand be easily changed or made of a higher quality material. It is also advantageous that the guard ring is formed insulating, whereby preferably a spacer made of a conductive material can be used.

The present invention will be explained in more detail with reference to the accompanying schematic drawings.

Show:

1 shows an exemplary representation of a steam cutting device; FIG. 2 is an exemplary illustration of the cross section of the steam plasma burner; FIG. 3 shows an exemplary representation of the nozzle; 4 shows a further exemplary representation of the nozzle; 5 shows an exemplary representation of the protective cap; 6 shows an exemplary representation of the screw sleeve; 7 shows a further exemplary representation of the screw sleeve; 8 shows an exemplary illustration of the receiving element; 9 shows a further exemplary representation of the receiving element; Fig. 10 is an exemplary view of the guard ring; 11 shows a further exemplary representation of the guard ring; Fig. 12 is an exemplary illustration of the spacer; and Fig. 13 is another exemplary illustration of the spacer. 3 AT 504 409 B1

By way of introduction, it is stated that identical parts of the exemplary embodiment are given the same reference numerals.

In Fig. 1, a steam cutting device 1 is shown with a base unit 1a for a steam cutting process. The base unit 1a comprises a power source 2, a control device 3 and a blocking element 4 associated with the control device 3. The blocking element 4 is connected to a container 5 and a steam plasma burner 6 via a supply line 7, so that the water vapor plasma burner 6 has a liquid arranged in the container 5 8 can be supplied. The supply of the steam plasma burner 6 with electrical energy via lines 9, 10 from the power source. 2

For cooling the steam plasma burner 6 this is connected via a cooling circuit 11 at best with the interposition of a flow monitor 12 with a liquid container 13. When starting up the burner 6 or the steam cutting device 1, the cooling circuit 11 can be started by the control device 3 and thus a cooling of the burner 6 via the cooling circuit 11 can be achieved. To form the cooling circuit 11, the burner 6 is connected via cooling lines 14, 15 with the liquid container 13.

Furthermore, the steam cutting device 1 may have an input and / or display device 16, via which the most varied parameters or operating modes of the water vapor cutting device 1 can be set and displayed. The parameters set via the input and / or display device 16 are forwarded to the control device 3, which controls the individual components of the steam cutting device 1 accordingly.

Furthermore, the steam plasma burner 6 can have at least one operating element 17, in particular a pushbutton 18. About the control element 17, in particular the button 18, the user can notify by activating and / or deactivating the button 18 of the control device 3 from the burner 6 that a steam cutting process should be started or performed. Furthermore, presettings can be made, for example, on the input and / or display device 16, in particular the material to be cut, the liquid used and, for example, characteristics of the current and the voltage are predefined. Of course, further operating elements can be arranged on the burner 6, via which one or more operating parameters of the steam cutting device 1 are set by the burner 6. For this purpose, these controls can be connected directly via lines or via a bus system with the steam cutting device 1, in particular the control device 3.

The control device 3 activates after pressing the button 18, the individual components required for the steam cutting process. For example, first a pump (not shown), the blocking element 4 and the current source 2 are driven, whereby a supply of the burner 6 with the liquid 8 and electrical energy is introduced. Subsequently, the control device 3 activates the cooling circuit 11, so that a cooling of the burner 6 is made possible. By supplying the burner 6 with the liquid 8 and with energy, in particular with current and voltage, the liquid 8 is now in the burner 6 in a gas 19, in particular in plasma, converted at high temperature, so that by the burner from the sixth outflowing gas 19, a cutting process on a workpiece 20 can be performed. For a cutting process on the workpiece 20 with the burner 6, which is shown in detail in Fig. 2, an arc is additionally required. The arc is ignited by the control device 4 or by pressing the button 18 and burns accordingly between a cathode 35, which is integrated in the burner 6 and preferably connected to the negative pole of the power source 2, and an anode formed by a nozzle 21 is connected and connected to the positive pole of the power source 2. When the burner 6 approaches the workpiece 20 according to the invention, the positive pole of the current source 2 is switched from the nozzle 21 to the workpiece 20, whereby the arc through the gas 19 correspondingly through an outlet opening 22 in the nozzle 21st is driven to the outside and thus burns between the cathode 35 and the workpiece 20. For this purpose, the current is increased by the control device 4, whereby, for example, the workpiece 20 can be separated.

In a cutting process, in particular by the burning arc correspondingly high temperatures and contaminants on the nozzle 21, whereby the diameter of the outlet opening 22 can shrink or change the shape. Furthermore, the arc causes a wear of the nozzle 21. This can have a negative effect on the cutting process. As a result, the nozzle 21 must be changed after a certain number or a certain duration of cutting processes.

This is done, for example, such that the nozzle 21, which is fastened with a screw on the burner 6, is unscrewed with a corresponding tool.

According to the invention the change of the nozzle 21 is simplified so that it can be carried out without tools. For this purpose, the burner in the region of the nozzle 21 is enveloped by a protective cap 23, which is a component of the housing of the burner 6. This protective cap 23 has a recess 24 in the region where the protective cap 23 encloses the nozzle 21. This recess 24 receives the nozzle 21 against rotation, whereby by rotating the protective cap 23, the nozzle 21 is taken accordingly. Thus, a change of the nozzle 21 preferably be made such that the user of the steam cutting device 1, the cap 23 rotates with one hand. As a result, the nozzle 21 is released from a base body 69 of the burner 6 and can be changed. The attachment of the nozzle 21 is also effected by a rotational movement. When changing the nozzle 21, however, the cap 23 remains on the burner 6, that is, by the rotational movement, the nozzle 21 is released from its attachment and, for example, then by a longitudinal displacement of the cap, the nozzle 21 can be ejected from the recess 24, however the protective cap 23 is held after the ejection of the nozzle 21 on the burner 6 and remains at this, so that then simply just a new nozzle 21 has to be inserted or inserted into the recess 24 and is in turn attached via a rotary movement.

So that the change of a nozzle 21 according to the invention is possible, the protective cap 23 and the nozzle 21 are designed accordingly, as can be seen from FIGS. 3 to 11.

In Figs. 3 and 4, the nozzle 21 is shown. Essentially, the nozzle 21 is formed of two parts, an inner part 25 and an outer part 26. In this case, the inner part 25 is in the assembled burner 6 in the protective cap 23, wherein the outer part 26 is correspondingly outside the protective cap 23. The outer part 26 is conical in shape, that is, it is designed as a conical region 26, wherein the tip of the conical outer part 26 forms one end of the nozzle 21. Furthermore, the tip of the conical outer part 26 is cut off substantially normal to the longitudinal axis 27 of the nozzle 21. In the resulting surface 28 is the outlet opening 22 whose center is located on the longitudinal axis 27. By the conical outer part 26 of the nozzle, the gas 19 is concentrated at the outlet opening 22, whereby a cutting operation is made possible.

The inner part 25 is essentially subdivided into four partial areas. The first portion 29 is formed by a ring or a projection 29, which has the largest outer diameter of the nozzle 21. For example, the ring has an outer diameter of 20 mm and a thickness of 2 mm. As a result, the ring protects the other portions of the inner part 25 of the nozzle from contamination caused, for example, by a cutting process. The second portion 30 or driver portion 30 of the inner part 25 is formed by a hexagon and serves to entrain the nozzle 21 by the rotational movement of the protective cap 23. The size of the hexagon, for example, selected such that the six edges of the 5 AT 504 409 B1

Hexagon with the outer diameter of the ring of the first portion 29 complete. This results, for example, in a distance between two opposite edges of 17 mm. The hexagon then serves for the tool-free change of the nozzle 21. The third portion 31 as well as the first portion 29 is formed as a ring, but this ring has a smaller outer diameter. This is chosen so that the hexagon covers the ring when the viewing direction is selected from the outer part 26 to the inner part 25. For example, this ring has an outer diameter of 16 mm and a thickness of 3 mm. Likewise, the ring may have a longitudinal groove 32 at the transition to the hexagon. This ring of the portion 31 preferably serves as a so-called centering ring 31 and as a current transition for the generally positively poled nozzle 21. About the centering the outlet opening 22 of the nozzle 21 is exactly centered on the longitudinal axis 68 of the burner 6. Thus, the longitudinal axis 27 of the nozzle 21 and the longitudinal axis 68 of the burner 6 form an axis. The fourth portion 33 or attachment region 33 of the inner part 25 of the nozzle 21 is formed as an external thread 34, wherein the outer diameter of the external thread 34 substantially corresponds to the diameter of the ring of the third portion 31, ie 16 mm. The external thread 34 serves primarily for fastening the nozzle 21 to the burner 6, which has a corresponding internal thread 35 on a base body 69 of the burner 6. Similarly, the external thread 34 serves secondarily for the passage of current to the nozzle 21, wherein the external thread 34 does not extend over the entire length of 7 mm of the fourth portion 33. This results in the transition from the fourth portion 33 to the third portion 31, a groove 67 of about 2 mm, which receives a sealing ring 36. The sealing ring 36 has an outer diameter which essentially corresponds to the outer diameter of the external thread 34 and of the ring in the third partial region 31, ie 16 mm. The sealing ring 36 prevents unwanted escape of the gas 19 at a location other than the outlet opening 22. Likewise, the nozzle 21 has a recess 37 and inner bore 37, which connects the inner part 25 and the outer part 26. Of course, the inner bore 37 merges with the transition from the inner part 25 in the outer part 26 in a conical shape and is connected to the outlet opening 22. Likewise, the inner bore 37 serves to receive the cathode 38, whereby the inner bore 37 is formed corresponding to the cathode 38.

In a cutting process, the nozzle 21 is heated by the arc accordingly. This heat is preferably returned to the burner 6, where this in turn is used to form the gas 19 from the liquid 8. This is called regenerative cooling. For this purpose, the nozzle 21 is made of a material which has a good thermal conductivity and a good electrical conductivity, preferably copper. Likewise, the nozzle 21 has a corresponding cross-section, so that the recirculated heat can be used optimally.

So that now the nozzle 21 can be changed without tools, the protective cap 23, which receives the nozzle 21, must be shaped accordingly.

The protective cap 23 according to FIG. 5 consists essentially of a threaded sleeve 39, a receiving element 40 located in the threaded sleeve 39 and a protective ring 41. In this case, the receiving element 40 is pressed, for example, into the threaded sleeve 39, wherein the protective ring 41 is releasably secured to the threaded sleeve 39 is. So that a certain, required distance exists for a cutting process between the nozzle 21 and the workpiece 20, a spacer 42 is attached to the protective ring 41. The shape of the protective cap 23 is adapted to the structure of the burner 6, so that it can be fixed in a form-fitting manner to the burner 6 and, accordingly, a current transition to the nozzle 21 is produced.

The screw 39 is made of an electrically insulating material, such as ceramic or plastic, whereby the electrically conductive receiving element 40 is protected. The shape of the screw 39, as can be seen from FIGS. 6 and 7, corresponds to two tubes 43 and 44 of different diameter arranged one inside the other. This results in a recess 45, which can receive the receiving element 40 accordingly, ie 6 AT 504 409 B1 is formed corresponding to the receiving element 40. At an end face 46 of the tube 44, at least one recess 47, preferably two recesses 47, is arranged. These recesses 47 are used for releasably securing the guard ring 41st

The electrically conductive receiving element 40, as shown in FIGS. 8 and 9 can be seen, for example, made of a gold-plated metal or brass. In principle, the receiving element 40 can be subdivided into two regions, preferably into a region 48 within and to the other region 49 outside the threaded sleeve 39. The region 48 is constructed substantially from a plurality of tubes with different diameters. This results in a corresponding inner recess 50, which is designed form-fitting to the burner 6. Thus, the protective cap 23, which contains the receiving element 40, be attached to the burner 6 via a snap ring 51. Likewise, a conductive connection, preferably to the positive pole of the current source 2, is produced via the region 39 of the receiving element 40. The area 49 serves to receive the nozzle 21, whereby it is formed substantially corresponding to the inner part 25 of the nozzle 21. Therefore, the current transfer from the receiving element 40 to the nozzle 21 via the region 49. Thus, the area 49, the hexagon of the nozzle 21, ie the second portion 30, on, thus has a hexagonal opening 52 (which corresponds to the recess 24) on. Thus, the hexagonal opening 52 is designed corresponding to the hexagon of the second portion 30 of the nozzle 21, whereby the nozzle 21 is received against rotation by the receiving element 40 and a current transfer is given to the nozzle 21. As a result, the first portion 29 of the inner part 25 of the nozzle 21 rests against the end face 53 at the end of the region 49 of the receiving element 40. Likewise, the hexagon of the nozzle 21 abuts against the receiving element 40, i. that after the hexagonal opening 52, ie in the direction of the inner region 48 of the receiving element 40, a bearing surface 54 is present. The bearing surface 54 results from this, since the receiving element 40 receives the third portion 31 of the nozzle 21 in a form-fitting manner. The end face 53 and the bearing surface 54, which are covered accordingly by the nozzle 21, cause the protective cap 23 can be fixed via the nozzle 21. Likewise, it results at the end face 53 and at the bearing surface 54 that a current transition takes place for a cutting process on the nozzle 21. The current transfer to the nozzle 21 thus takes place via the region 49 which is located outside of the insulating threaded sleeve 39. So that this does not lead to unwanted contacts or short circuits, the area 49 is insulated with a guard ring 41.

The guard ring 41 is preferably detachable and thus changeably connected to the protective cap 23 or the threaded sleeve 39. The guard ring 41 is made of an electrically insulating material, such as ceramic, and preferably protects the receiving element 40 and the protective cap 23 from excessive heating during a cutting process. For this purpose, the protective ring 41 is designed in such a way, as shown in FIGS. 10 and 11, that this substantially encloses the region 49 of the receiving element 40 in a form-fitting manner. For this purpose, the guard ring 41 has a corresponding recess 56, corresponding to the region 49 of the receiving element 40, on. The recess 56, which forms an inner side of the guard ring 41, furthermore has elevations 57, for example two. In addition, at least one fastening element 59 is arranged on the end face 58, wherein the fastening elements 59 firmly and detachably connect the guard ring 41 by a rotational movement with the protective cap 23. Preferably, two fastening elements 59 are arranged on the end face 58. The fasteners 59 engage in the corresponding recesses 47 a. This is supported by the elevations 57, since the receiving element 40 has a corresponding recess. Thus, the guard ring 41 and the fasteners 59 can be inserted into the recess 47 only if the portion of the recess 47, which receives the fasteners 59, the fasteners 59 and the elevations 57 form a line. Subsequently, the guard ring 41 is fixed by the rotary movement, that is to say a bayonet closure, to the protective cap 23 or threaded sleeve 39. Furthermore, the guard ring 41 has a recess 61 on its rounded outer side 60. This recess 61 serves to secure the spacer 42, which protects the nozzle 21 from accidental contact. 7 AT 504 409 B1

The spacer 42 consists essentially of two rings 62 and 63 as shown in FIGS. 12 and 13 can be seen, wherein a ring 62 has at least one element 64 which defines the distance between the nozzle 21 and workpiece 20. Preferably, the ring 62 has two elements 64, which are for example U-shaped. Thus, the nozzle 21 is protected from accidental contact and has a defined distance from the workpiece 20. The ring 62 serves to attach the spacer 42 to the recess 61 of the guard ring 41, which is why the ring 62 through the opening 65 is stretchable. The second ring 63 is attached to the elements 64 and gives the spacer 42 the necessary stability. This is achieved in that the ring 63 surrounds the nozzle 21 in the conical part, ie the outer part 26. This is done, for example, in the central region of the outer part 26 of the nozzle 21. For this purpose, the ring 63 is attached to the elements 64. It is also possible that the rings 62 and 63 have the shape of an ellipse.

Thus, a cutting process can be performed with the steam cutting device 1, wherein the protective cap 23 and the nozzle 21 must be firmly connected to the burner 6, so that the passage of electricity and leakage of the gas 19 is ensured only at the outlet opening 22 of the nozzle 21.

Such a solid compound is produced according to the invention such that the nozzle 21 is inserted into the receiving element 40 of the protective cap 23. Subsequently, the protective cap 23 is placed on the burner 6, whereby it is independently held on the burner 6 via a spring 66 or a spring element 66 and the snap ring 51 and in the direction of the longitudinal axis 27 is displaceable. By a jerky movement, the protective cap 23 can be removed from the burner 6. Of course, it is also possible that the protective cap 23 for receiving the nozzle 21 is already on the burner 6. By a rotary movement of the protective cap 23, the nozzle 21 rotates about the rotationally fixed connection via the hexagon of the nozzle 21. This causes the external thread 34 of the fourth portion 33 of the nozzle 21 corresponding to the internal thread 35 in the burner 6 connects. Thus, the protective cap 23 is fixed by the nozzle 21 and made the solid connection between the nozzle 21 and the protective cap 23 and the burner 6. The rotational movement takes place in an advantageous manner by hand, whereby no tool is required.

Likewise, no tool is required for a change of the nozzle 21. Here, in the same manner as in the attachment of the nozzle 21, the protective cap 23 unscrewed accordingly, which also dissolves the nozzle 21 from the internal thread 35 in the burner 6. The rotational movement of the protective cap 23 is supported by the spring 66, which is arranged in the burner 6 and exerts a corresponding force on the receiving element 40. Thus, the force of the spring 66, the cap 23 can not solve uncontrolled from the burner 6, the cap 23 is held by the snap ring 51 on the burner 6. At this position, the protective cap 23, the nozzle 21 is already released from the internal thread 35 in the burner 6, whereby a rotational movement of the cap 23 only causes a so-called idle. Likewise, at this position of the protective cap 23, the nozzle 21 falls out of the protective cap 23 due to gravity. In order for the spacer 42 not to obstruct a change of the nozzle 21, the attachment of the spacer 42 is carried out such that the spacer 42 with the nozzle 21 of the Protective cap 23 is released. It is also possible that the spacer 42 is a part of the nozzle 21 is formed. If the change of the nozzle 21 immediately after a cutting process, the nozzle 21 is heated accordingly. This can cause the nozzle 21 to expand slightly, whereby the nozzle 21 does not automatically detach from the protective cap 23. In this case, the nozzle 21 can be solved by a jerky backward movement of the protective cap 23 thereof. Here, the spring 66 causes the protective cap 23 is moved forward again to attach a new nozzle 21 to the burner 6.

Of course, the protective cap 23 shown in FIGS. 2 to 13, the nozzle 21 and the spacer 42 is only one embodiment variant. For example, it would be possible to design the conical outer part 26 of the nozzle 21 such that it functions as the first

Claims (5)

8 AT 504 409 B1 portion 29 of the inner part 25 of the nozzle 21 takes over, so protects against contamination. Likewise, it is of course possible that the preferred diameter of the outlet opening 22 of the nozzle 21 of 0.7 mm is adjusted according to the application. It is also possible that the second portion 30 of the nozzle 21 of an octagon or a circle, which has one or more laterally projecting webs, which are received by the recess 52 of the receiving element 40 correspondingly secured against rotation. Protective ring (41) for a steam plasma burner (6), which protects the components of the steam plasma burner (6) from thermal effects and insulated current-carrying components, wherein at one end face (58) at least one fastening device (59) for releasably mounted on a Protective cap (23) is arranged, and a recess (56) is provided which is formed during assembly for receiving and enclosing a nozzle (21), characterized in that the fastening devices (59) for receiving in corresponding recesses (47) of Protective cap (23) and for locking in the recesses (47) are formed by a rotational movement. Second guard ring (41) according to claim 1, characterized in that on the inside of the recess (56) at least one elevation (57) is provided. 3. Guard ring (41) according to claim 1 or 2, characterized in that on the inside of the recess (56) two elevations (57) are provided. 4. guard ring (41) according to one of claims 1 to 3, characterized in that two fastening devices (59) are provided. 5. guard ring (41) according to one of claims 1 to 5, characterized in that on the outer side (60) has a groove or recess (61) for fixing a spacer (42) is provided. Including 8 sheets of drawings