Plasma torches and processes for coating surfaces

Abstract

The invention relates to a plasma torch (10) for coating surfaces, wherein the plasma torch (10) has a gas / plasma channel for generating a plasma jet (26) directed along a first direction (X). The plasma torch (10) is designed to be operated within a working distance range measured along the first direction (X) from a surface (24) to be coated, such that the plasma jet (26) strikes the surface (24) to be coated in a plasma impact zone (44).The plasma torch (10) has a coating material injector (14) for injecting coating material (28) into the plasma jet (26), wherein the plasma torch (10) is designed, in particular the coating material injector (14) is arranged relative to the gas / plasma channel, such that the coating material (28) is injected along a direction different from the first direction (X) in the plasma jet (26), so that the coating material (28) is melted and entrained by the plasma jet (26), so that a coating material jet (30) is generated which has a velocity component in a first direction (X) parallel to the plasma jet (26) and a velocity component in a second direction (Y) perpendicular to the plasma jet (26).During operation of the plasma torch (10), the coating material jet (30) strikes the surface (24) to be coated in a coating material impact zone (46) offset along the second direction (Y) relative to the plasma impact zone (44) within the working distance range. The plasma torch (10) has a plurality of gas nozzles (16, 18, 20, 22) for generating gas jets (32, 34) for cooling the coated surface (24) and / or cleaning the surface (24) to be coated. The gas nozzles (16, 18, 20, 22) are arranged and / or aligned on the plasma torch (10) such that, during operation of the plasma torch (10) within the working distance range, the gas jets (32, 34) strike the coated and / or to-be-coated surface (24) in gas impact zones (36, 38, 40, 42). hit.At least one first gas nozzle (16) is arranged and / or aligned on the plasma torch (10) relative to the plasma channel (12) in such a way that, during operation of the plasma torch (10), within the working distance range, a first gas impact zone (36), in which a first gas jet generated by means of the first gas nozzle (16) hits the surface (24), is arranged further along the second direction (Y) relative to the plasma impact zone (44) than the coating material impact zone (46).

Description

[0001] The invention relates to a plasma torch and a method for coating surfaces according to the independent claims.

[0002] Plasma torches according to the invention heat a gas mixture to over 10,000 °C using an arc. The coating material to be applied to the surface to be coated is sprayed into this hot plasma jet as a fine powder. The powder is melted in the plasma jet, heated to approximately 2,500 °C, and sprayed onto the surface as a jet of coating material at a speed of approximately 100 m / s.

[0003] In particular, the invention relates to a plasma torch which is suitable in its size and power for coating the running surfaces of cylinders of reciprocating internal combustion engines, and to a method for coating the running surfaces of cylinders of reciprocating internal combustion engines.

[0004] The engine blocks of modern reciprocating piston internal combustion engines are typically made of cast aluminum, which allows for low component weight combined with positive cooling properties. The running surfaces, especially in cast aluminum cylinders, are typically coated with a thin layer of a wear-resistant, harder material, also to achieve lower friction values ​​between piston and cylinder and the necessary abrasion resistance for long-term operation.

[0005] It is known from practice that plasma torches of the type in question have gas nozzles with which gas jets are generated. These serve to cool and / or clean the surface to be coated. The gas nozzles are typically arranged and aligned so that the gas jets are arranged around the plasma jet. If the plasma torch is moved relative to the surface during the coating process, a gas jet that strikes the surface before the coating material jet can be used to clean the surface to be coated. A gas jet that strikes the surface after the coating material jet can be used to cool the coated surface.

[0006] In the state-of-the-art processes, the aim is that when the plasma torch is moved relative to the surface to be coated, the surface is first hit by a gas jet, then by the coating material jet, and finally by another gas jet. In this way, the cleaning and cooling functions of the gas jets can be utilized.

[0007] Plasma torches are known from the prior art, for example from DE 2012 003 306 A1, in which the gas nozzles are arranged around the gas / plasma channel. As a result, the resulting gas impingement zones of the gas jets are arranged around the plasma impingement zone of the plasma jet.

[0008] However, in such plasma torches known from practice, it has been shown that the cooling and cleaning functions of the gas jets depend on the direction of movement of the plasma torch. In particular, it has been found that either the cooling effect or the cleaning effect can be impaired by the direction of movement.

[0009] The invention is therefore based on the object of providing a plasma torch and a method for coating surfaces in which the cooling and / or cleaning effect of the gas jets is less dependent on the direction of movement of the plasma torch relative to the surface.

[0010] This object is achieved by a plasma torch and a method having the features of the independent claims. The dependent claims relate to advantageous embodiments.

[0011] The plasma torch for coating surfaces has a gas / plasma channel for generating a plasma jet directed along a first direction. The plasma torch has, in particular, means for generating an arc to heat gas within the gas / plasma channel and thus generate the plasma.

[0012] The plasma torch is designed to be operated within a working distance range measured along the first direction from a surface to be coated. This results in the plasma jet impinging on the surface to be coated in a plasma impact zone.

[0013] The plasma torch further comprises a coating material injector for injecting coating material, in particular powdered, into the plasma jet. The plasma torch is designed such that the coating material is injected into the plasma jet along a direction different from the first direction. The direction in which the coating material is injected results, in particular, from the arrangement of the coating material injector relative to the gas / plasma channel.

[0014] As a result, the coating material is melted and entrained by the plasma jet, generating a coating material jet. In connection with the present invention, it has been found that a coating material jet generated in this way has a velocity component in a first direction parallel to the plasma jet and a velocity component in a second direction perpendicular to the plasma jet.In other words, because the injection of the coating material into the plasma jet takes place in a direction different from the first direction, the resulting coating material jet receives, in addition to the velocity component directed parallel to the plasma jet along the first direction, a second velocity component in a second direction, which ultimately results from the fact that the coating material is not injected into the plasma jet in a direction parallel to the direction of the plasma jet.

[0015] When the plasma torch is operated within the working distance range, the coating material jet hits the surface to be coated in a coating material impact zone offset along the second direction relative to the plasma impact zone.

[0016] In state-of-the-art plasma torches, the gas nozzles for generating the gas jets are arranged and aligned with the orientation of the plasma jet. When using a state-of-the-art plasma torch, the gas jets therefore hit the surface in gas impact zones arranged around the plasma impact zone. Since it has been found that the coating material impact zone is offset relative to the plasma impact zone along the second direction, the problem described above when moving the plasma torch relative to the surface can now be explained. If the plasma torch is moved along the second direction, the offset of the coating material impact zone along the second direction can result in the coating material hitting the surface before the gas. In other words, the coating material impact zone precedes all gas impact zones.The gas can therefore only exert its cooling effect, not its cleaning effect. However, if the plasma torch is moved relative to the surface in the opposite direction to the second direction, the opposite effect can occur. All gas jets hit the surface before the coating material jet. While the surface can be cleaned in this way, after the coating material jet hits the surface, the gas jets no longer produce any cooling effect. This is clearly explained by the fact that, with corresponding movements, the coating material impact zone follows the gas impact zones.In addition to the extreme case in which the cooling effect or the cleaning effect is no longer achieved at all, depending on how far the coating material impact zone is offset along the second direction relative to the plasma impact zone, transitional states are also possible in which the corresponding cooling effect or cleaning effect is only achieved to a reduced extent due to the offset of the coating material impact zone.

[0017] The plasma torch has a plurality of gas nozzles for generating gas jets, for example, air jets, for cooling the coated surface and / or for cleaning the surface to be coated. Furthermore, the gas nozzles are arranged and / or aligned on the plasma torch such that, during operation of the plasma torch, the gas jets impinge on the coated surface and / or the surface to be coated in gas impingement zones within the working distance range.

[0018] The object is now achieved in particular in that at least one first gas nozzle is arranged and / or aligned relative to the plasma channel on the plasma torch such that, during operation of the plasma torch within the working distance range, a first gas impingement zone in which a first gas jet generated by means of the first gas nozzle impinges on the surface is arranged further offset along the second direction relative to the plasma impingement zone than the coating material impingement zone.

[0019] Such an arrangement and / or orientation of the first gas nozzle results in the first gas jet generated impinging on the surface before the coating material jet when the plasma torch moves along the second direction, thus enabling the desired cleaning effect to be achieved. Furthermore, the arrangement / or orientation of the first gas nozzle results in the first gas jet impinging on the surface after the coating material jet when the plasma torch moves counter to the second direction relative to the surface, thus enabling the desired cleaning effect to be achieved. In other words, while the gas impingement zones of conventionally aligned and / or arranged gas nozzles trail the coating material zone when moving along the first direction, the first gas impingement zone leads the coating material zone.However, when moving in the opposite direction to the second direction, where the gas impingement zones of conventionally aligned and / or arranged gas nozzles precede the coating material zone, the first gas impingement zone follows the coating material impingement zone. This counteracts the problem described above and ensures the sequence of impingement of gas, coating material, and gas to a sufficient degree to achieve both the cleaning and cooling effects, regardless of the direction of movement of the plasma torch relative to the surface.

[0020] Furthermore, a second gas nozzle can be arranged and / or aligned relative to the plasma channel on the plasma torch such that, when the plasma torch is operated within the working distance range, a second gas impingement zone, in which a second gas jet generated by the second gas nozzle strikes the surface, is arranged further offset along the second direction relative to the plasma impingement zone than the coating material impingement zone. A correspondingly arranged second gas impingement zone enables an even more effective decoupling of the cleaning or cooling effect of the gas jets from the direction of movement of the plasma torch relative to the surface.

[0021] The first and second gas nozzles can be arranged and / or aligned on the plasma torch relative to the plasma channel in such a way that, when the plasma torch is operated within the working distance range, the first gas impact zone is offset relative to the coating material impact zone along a third direction perpendicular to the first and second directions, and the second gas impact zone is offset opposite to this in a third direction perpendicular to the first and second directions. Such an arrangement of the first and second gas impact zones offset along the third direction in particular ensures that, during diagonal movements of the plasma torch, i.e. movements which have a directional component parallel to the second and third directions, a gas jet strikes the surface before and after the coating material jet. Advantageously, this creates an overlap region between the two impact zones between the first and second gas impact zones, so that, despite the movements along the third direction orThe arrangement of the first and second gas impact zones offset relative to the coating material impact zone, counter to the third direction, ensures that a gas jet strikes the surface before and after the coating material jet, even when the plasma torch moves exactly along and counter to the second direction relative to the surface.

[0022] Preferably, the gas nozzles are arranged and / or aligned relative to the plasma channel on the plasma torch such that, during operation of the plasma torch within the working area, the gas impingement zones are distributed around the coating material impingement zone.

[0023] It is consistent with the fundamental understanding underlying the present invention to arrange and / or align the gas nozzles such that the gas impingement zones are distributed around the coating material impingement zone and not, as is possible in the prior art, around the plasma impingement zone. In this way, the coating material impingement zone can preferably be surrounded by the gas impingement zones in such a way that, as the plasma torch moves along the surface in all directions, it is ensured that first a gas jet, then a coating material, and finally another gas jet impinge on the surface to be coated.

[0024] This can be achieved in particular in such a way that the gas nozzles are arranged and / or aligned in such a way that at least two gas impingement zones, which are arranged offset relative to one another along the second direction, are arranged offset along and opposite to the third direction relative to the coating material impingement zone. The gas impingement zones offset relative to one another along the second direction are arranged in particular in such a way that one impingement zone is arranged further offset relative to the plasma impingement zone along the second direction than the coating material impingement zone, and one is arranged less offset relative to the plasma impingement zone along the second direction than the coating material impingement zone. It has been shown that in this way, sufficient enclosure of the coating material impingement zone on all sides can be achieved with just four gas nozzles.This is particularly due to the fact that the real gas impact zones are not sharply defined areas, but rather become blurred towards their edges, so that overlapping areas form between gas impact zones in which the gas of two neighboring gas jets impacts the surface.

[0025] The plasma torch has in particular a power of more than 10 kW, preferably power between 12 kW and 20 kW and particularly preferably power of approximately 12 kW to 16 kW.

[0026] The size of the plasma torch is preferably designed so that it can be inserted into and still moved within cylinders with a maximum diameter of 100 mm, more preferably into cylinders with a maximum diameter of 80 mm, and especially preferably into cylinders with a maximum diameter of 75 mm. This results in a particularly compact plasma torch, where space savings are particularly important.

[0027] The dimensions, height and width, extending at right angles to the longitudinal direction of the plasma torch, in particular parallel to the second direction, are each preferably a maximum of 50 mm, more preferably a maximum of 40 mm, and particularly preferably a maximum of 35 mm. The invention was made in particular for a plasma torch which has a height, in particular parallel to the first direction, and a width, in particular parallel to the third direction, of 25 mm x 35 mm, and whose length is approximately 75 mm. During operation of the plasma torch, the longitudinal direction preferably corresponds to its insertion direction into a cylinder to be coated.

[0028] The process for coating surfaces can be carried out in particular by means of a plasma torch as described above.

[0029] The method involves generating a plasma jet using a plasma torch. The plasma jet impinges on a surface to be coated in a plasma impingement zone. A coating material, particularly a powdered coating material, is injected into the plasma jet. The coating material injected into the plasma jet is melted and entrained by the plasma jet. This results in a coating material jet that has a velocity component in a first direction parallel to the plasma jet and a velocity component in a second direction perpendicular to the plasma jet. The coating material jet subsequently impinges on the surface to be coated in a coating material impingement zone offset along the second direction relative to the plasma impingement zone.

[0030] The method further provides that gas jets, for example air jets, impinge on the coated surface and / or the surface to be coated in gas impingement zones for cooling the coated surface and / or cleaning the surface to be coated.

[0031] The object is achieved by the method in particular in such a way that a first gas jet is aligned in such a way that at least one first gas impact zone, in which the first gas jet impacts the surface, is arranged offset further along the second direction relative to the plasma impact zone than the coating material impact zone.

[0032] Such an orientation of the first gas jet means that when the plasma torch moves along the second direction, the first gas jet hits the surface before the coating material jet, thus enabling the desired cleaning effect. Furthermore, the orientation of the first gas jet means that when the plasma torch moves opposite to the second direction relative to the surface, the first gas jet hits the surface after the coating material jet, thus enabling the desired cleaning effect. In this way, the problem described at the beginning is counteracted and the sequence of impact of gas, coating material, and gas is ensured to a sufficient extent to be able to bring about both the cleaning effect and the cooling effect, regardless of the direction of movement of the plasma torch relative to the surface.

[0033] The method may further provide for a second gas jet to be oriented such that at least one second gas impingement zone, in which the second gas jet impinges on the surface, is offset further along the second direction relative to the plasma impingement zone than the coating material impingement zone. A correspondingly arranged second gas impingement zone enables an even more effective decoupling of the cleaning or cooling effect of the gas jets from the direction of movement of the plasma torch relative to the surface.

[0034] The method can further provide that the first and second gas jets are aligned such that the first gas impingement zone is offset relative to the coating material impingement zone along a third direction perpendicular to the first and second directions, and the second gas impingement zone is offset relative to the coating material impingement zone. Such an offset arrangement of the first and second gas impingement zones along the third direction results, in particular, in the fact that, during diagonal movements of the plasma torch—i.e., movements that have a directional component parallel to the second and third directions—the impingement of a gas jet onto the surface is ensured before and after the coating material jet.

[0035] The method can, in particular, provide for the gas jets to be aligned such that the gas impingement zones are distributed around the coating material impingement zone, with adjacent gas impingement zones, in particular, overlapping in their diffusely tapered edge regions. In this way, the coating material impingement zone can preferably be surrounded by the gas impingement zones in such a way that, when the plasma torch moves along the surface in all directions, it is ensured that first a gas jet, then the coating material jet, and finally another gas jet impinge on the surface to be coated.

[0036] Due to the orientation of the gas jets, the gas impingement zones are arranged in particular such that at least two gas impingement zones, which are offset relative to one another along the second direction, are offset relative to the coating material impingement zone along and opposite to a third direction perpendicular to the first and second directions. It has been shown that in this way, sufficient coverage of the coating material impingement zone on all sides can be achieved with just four gas jets.

[0037] The method can, in particular, provide that the surface is a running surface of a cylinder of a reciprocating piston engine. In this case, the method is carried out in particular such that the plasma torch is aligned relative to the cylinder during the method such that the second direction is oriented parallel to the cylinder axis. Such an alignment is advantageous since the relative arrangement of the coating material injector and plasma channel typically means that the dimensions of the plasma torch along the second direction are larger than along the first and / or third direction. Such a plasma torch can therefore most effectively be introduced into the cylinder whose running surface is to be coated with its second direction oriented parallel to the cylinder axis.To completely coat the cylinder's running surface, it is then necessary to move the plasma torch in directions along and / or opposite to the second direction, or in directions that have a corresponding directional component. The process is therefore particularly suitable for coating the running surfaces of cylinders in reciprocating piston engines.

[0038] Furthermore, the method can provide for air extraction, in particular with a predominant flow direction opposite or along the second direction. Particularly when coating the running surfaces of cylinders, a corresponding orientation of the air extraction is advantageous for equipment-related reasons. The air extraction can then take place, in particular, along or opposite the direction from which the plasma torch is introduced into the cylinder. The air extraction, in particular along or opposite the second direction, can additionally influence the flow conditions of the gas, plasma, and coating material jets. This effect can lead to a further exacerbation of the problematic effect described above in prior art methods, which are carried out in particular with prior art plasma torches.The method according to the invention for coating surfaces, in particular by means of a plasma torch described above, is therefore particularly robust against corresponding disruptive influences that may result from the extraction.

[0039] Further practical embodiments of the invention are described below in conjunction with the drawings. They show: Fig. 1 a schematic perspective view of an exemplary plasma torch, Fig. 2 an exemplary schematic sectional view of a plasma torch according to the prior art when carrying out a method according to the prior art, Fig. 3 the arrangement of the gas, plasma and coating material impact zones relative to each other when carrying out a prior art method with a prior art plasma torch, Fig. 4 an exemplary schematic sectional view of a plasma torch during the implementation of a method showing the exemplary course of a second gas jet, Fig. 5 is an exemplary schematic sectional view of a plasma torch during the implementation of a method showing the exemplary path of a second gas jet in an alternative embodiment, Fig. 6 shows a further exemplary schematic sectional view of a plasma torch during the implementation of a method with illustration of the exemplary course of an exemplary fourth gas jet, Fig. 7 the arrangement of the gas, plasma and coating material impact zones relative to each other when carrying out an exemplary method with an exemplary plasma torch.

[0040] In Fig. Figure 1 shows a schematic perspective view of a typical plasma torch of the type in question. The plasma torch 10 shown as an example comprises a plasma channel 12, a coating material injector 14 (of which only the injector holder is shown in the example shown for illustrative reasons), and a plurality of gas nozzles 16, 18, 20, and 22 (four in the example shown).

[0041] In the Fig. 2 shows, by way of example, how the coating of an exemplary surface 24 is carried out in such a plasma torch 10 according to the prior art. In the plasma channel 12 oriented along a first direction X, a plasma jet 26 aligned along the first direction X is generated. By means of the coating material injector 14, in particular powdered coating material 28 is injected into the plasma jet 26 in a direction different from the first direction X and thus the direction of the plasma jet 26. The coating material 28 is melted and entrained by the plasma jet 26. This creates a coating material jet 30 which has a velocity component in a first direction X parallel to the plasma jet 26 and a velocity component in a second direction Y perpendicular to the plasma jet 26.As a result, the direction of the coating material jet 30 deviates from that of the plasma jet 26, the coating material jet 30 strikes the surface 24 at a different location than the plasma jet 26, as in . Fig. 2 is illustrated schematically.

[0042] According to the prior art, gas jets surrounding the plasma jet 26, for example the gas jets 32, 34 shown, are generated by means of the gas nozzles 16, 18, 20, 22. Due to the central cutting plane of the plasma torch 10, Fig. 2 accordingly only the second gas jet 32 ​​generated by the second gas nozzle 18 and the fourth gas jet 34 generated by the fourth gas nozzle 22 are shown.

[0043] In Fig. Figure 3 schematically shows the positions of the impact zones of the individual jets, which result from the prior art. The first gas jet, generated by the first gas nozzle 16, strikes the surface 24 in the first gas impact zone 36. The second gas jet 32, generated by the second gas nozzle 18, strikes the surface 24 in the second gas impact zone 38. The third gas jet, generated by the third gas nozzle 20, strikes the surface 24 in the third gas impact zone 40. The fourth gas jet 34, generated by the fourth gas nozzle 22, strikes the surface 24 in the fourth gas impact zone 42.

[0044] The plasma jet 26 generated in the plasma channel 12 strikes the surface 24 in the plasma impact zone 44, and the coating material jet 30 strikes the surface 24 in the coating material impact zone 46.

[0045] The coating material impingement zone 46 is offset relative to the plasma impingement zone 44 due to the velocity component of the coating material jet 30 parallel to the second direction Y. As a result, the gas impingement zones 36, 38, 40 and 42 according to the prior art surround the plasma impingement zone 44, but not the coating material impingement zone 46. The individual impingement zones 36, 38, 40, 42 and 44 are shown in the Fig. 3 and Fig. 7 is shown as sharply defined for simplification. In practice, however, the impact zones 36, 38, 40, 42 will have blurred edges, and in particular the gas impact zones 36, 38, 40, 42 will overlap in their blurred edges, so that zones arise between adjacent gas impact zones 36, 38, 40, 42 in which parts of two adjacent gas jets impinge on the surface 24.

[0046] In the Fig. 4 and Fig. 5 shows two exemplary possibilities of how the orientation of the second gas jet 32 ​​can be changed by means of a suitable arrangement and / or orientation of the gas nozzles, in the example shown exemplarily the second gas nozzle 18, so that the second gas impingement zone 38 is offset further along the second direction Y relative to the plasma impingement zone 44 than the coating material impingement zone 46. On the one hand, there is the possibility of changing the orientation of the second gas nozzle 18 compared to the prior art, as is shown in Fig. 4 is shown schematically. Accordingly, the second gas jet 32 ​​extends at a significant angle to the plasma jet 26. Alternatively or additionally, as shown in Fig. 5, the arrangement of the second gas nozzle 18 on the plasma torch 10 can be changed. In particular, by shifting the arrangement of the second gas nozzle 18 in the second direction Y, the position of the second gas impingement zone 38 can be shifted further along the second direction Y relative to the plasma impingement zone 44 and the coating material impingement zone 46.

[0047] Furthermore, as in Fig. 6, the arrangement and / or orientation of the third and fourth gas nozzles 20 and 22 can also be changed in order to displace the corresponding gas impingement zones 40 and 42 along the second direction Y. In particular, the third and fourth gas nozzles 20, 22 can be arranged and aligned such that the third gas impingement zone 40 and the fourth gas impingement zone 42 are arranged less offset along the second direction Y relative to the plasma impingement zone 44 than the coating material impingement zone 46.

[0048] In particular, the arrangement and alignment of the gas nozzles 16, 18, 20, 22 can Fig. 7 schematically illustrated arrangement of the individual impact zones, in which the gas impact zones 36, 38, 40 and 42 surround the coating material impact zone 46.

[0049] The features of the invention disclosed in the present description, the drawings, and the claims may be essential, both individually and in any combination, for the realization of the invention in its various embodiments. The invention may be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art. List of reference symbols 10 plasma torches 12 plasma channel 14 Coating material injector 16 first gas nozzle 18 second gas nozzle 20 third gas nozzle 22 fourth gas nozzle 24 Surface 26 Plasma beam 28 Coating material 30 coating material jet 32 second gas jet 34 fourth gas jet 36 first gas impact zone 38 second gas impact zone 40 third gas impact zone 42 fourth gas impact zone 44 Plasma impact zone 46 Coating material impact zone X first direction Y second direction Z third direction QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 2012 003 306 A1

[0007]

Claims

[1] Plasma torch (10) for coating surfaces, wherein the plasma torch (10) has a gas / plasma channel for generating a plasma jet (26) directed along a first direction (X), wherein the plasma torch (10) is designed to be operated within a working distance range measured along the first direction (X) from a surface (24) to be coated, so that the plasma jet (26) strikes the surface (24) to be coated in a plasma impact zone (44), wherein the plasma torch (10) has a coating material injector (14) for injecting coating material (28) into the plasma jet (26), wherein the plasma torch (10) is designed in such a way, in particular the coating material injector (14) is arranged relative to the gas / plasma channel, that the coating material (28) is injected into the plasma jet (26) along a direction different from the first direction (X), so that the coating material (28) is melted and entrained by the plasma jet (26), so that a coating material jet (30) is generated which has a velocity component in a first direction (X) parallel to the plasma jet (26) and a velocity component in a second direction (Y) perpendicular to the plasma jet (26), so that the coating material jet (30) strikes the surface (24) to be coated during operation of the plasma torch (10) within the working distance range in a coating material impact zone (46) offset along the second direction (Y) relative to the plasma impact zone (44), wherein the plasma torch (10) has a plurality of gas nozzles (16, 18, 20, 22) for generating gas jets (32, 34) for cooling the coated surface (24) and / or cleaning the surface (24) to be coated and is designed, in particular the gas nozzles (16, 18, 20, 22) are arranged and / or aligned on the plasma torch (10) in such a way that the gas jets (32, 34) impinge on the coated and / or to-be-coated surface (24) in gas impingement zones (36, 38, 40, 42) during operation of the plasma torch (10), characterized by , that at least one first gas nozzle (16) is arranged and / or aligned on the plasma torch (10) relative to the plasma channel (12) in such a way that during operation of the plasma torch (10) within the working distance range, a first gas impingement zone (36), in which a first gas jet generated by means of the first gas nozzle (16) impinges on the surface (24), is arranged further offset along the second direction (Y) relative to the plasma impingement zone (44) than the coating material impingement zone (46). [2] Plasma torch (10) according to claim 1, characterized bythat a second gas nozzle (18) is arranged and / or aligned relative to the plasma channel (12) on the plasma torch (10) in such a way that during operation of the plasma torch (10) within the working distance range, a second gas impingement zone (38), in which a second gas jet (32) generated by means of the second gas nozzle (18) impinges on the surface (24), is arranged further offset along the second direction (Y) relative to the plasma impingement zone (44) than the coating material impingement zone (46). [3] Plasma torch (10) according to claim 2, characterized bythat the first and the second gas nozzle (16, 18) are arranged and / or aligned relative to the plasma channel (12) on the plasma torch (10) in such a way that when the plasma torch (10) is operated within the working distance range, the first gas impingement zone (36) is arranged offset relative to the coating material impingement zone (46) along and the second gas impingement zone (38) is arranged offset relative to a third direction (Z) perpendicular to the first and second directions (X, Y). [4] Plasma torch (10) according to one of the preceding claims, characterized bythat the gas nozzles (16, 18, 20, 22) are arranged and / or aligned relative to the plasma channel (12) on the plasma torch (10) in such a way that, during operation of the plasma torch (10), the gas impingement zones (36, 38, 40, 42) are arranged distributed around the coating material impingement zone (46) within the working distance range, in particular in such a way that at least two gas impingement zones, which are arranged offset relative to one another along the second direction (Y), are arranged offset along and opposite to a third direction (Z) relative to the coating material impingement zone (46). [5] Method for coating surfaces (24), in particular by means of a plasma torch (10) according to one of the preceding claims, wherein a plasma jet (26) is generated by means of a plasma torch (10), which jet impinges on a surface (24) to be coated in a plasma impingement zone (44), wherein, in particular, powdered coating material (28) is injected into the plasma jet (26) in such a way that the coating material (28) is melted and entrained by the plasma jet (26), wherein the resulting coating material jet (30) has a velocity component in a first direction (X) parallel to the plasma jet (26) and a velocity component in a second direction (Y) perpendicular to the plasma jet (26), so that the coating material jet (30) strikes the surface (24) to be coated in a coating material impact zone (46) offset along the second direction (Y) relative to the plasma impact zone (44), wherein gas jets (32, 34) for cooling the coated surface (24) and / or cleaning the surface (24) to be coated impinge on the coated and / or surface to be coated (24) in gas impingement zones (36, 38, 40, 42), characterized by , that a first gas jet is aligned such that at least a first gas impingement zone (36) in which the first gas jet impinges on the surface (24) is arranged further offset along the second direction (Y) relative to the plasma impingement zone (44) than the coating material impingement zone (46). [6] Method according to claim 5, characterized by that a second gas jet (32) is aligned such that at least one second gas impingement zone (38) in which the second gas jet impinges on the surface 24 is arranged further offset along the second direction (Y) relative to the plasma impingement zone (44) than the coating material impingement zone (46). [7] Method according to claim 6, characterized bythat the first and the second gas jet (32) are aligned such that the first gas impingement zone (36) is arranged offset relative to the coating material impingement zone (46) along and the second gas impingement zone (38) is arranged offset against a third direction (Z) perpendicular to the first and second directions (X, Y). [8] Method according to one of claims 5 to 7, characterized by in that the gas jets (32, 34) are aligned in such a way that the gas impact zones (36, 38, 40, 42) are arranged distributed around the coating material impact zone (46), in particular in such a way that at least two gas impact zones (36, 38, 40, 42), which are arranged offset relative to one another along the second direction (Y), are arranged offset relative to the coating material impact zone (46) along and opposite to a third direction (Z) perpendicular to the first and second directions (X, Y). [9] Method according to one of claims 5 to 8, characterized bythat the surface (24) is a running surface of a cylinder of a reciprocating piston engine, in particular wherein the plasma torch (10) is aligned relative to the cylinder during the implementation of the method such that the second direction (Y) is oriented parallel to the cylinder axis. [10] Method according to one of claims 5 to 9, characterized by that air extraction takes place, in particular wherein the air extraction takes place with a predominant flow direction along or opposite to the second direction (Y) and / or along or opposite to the direction from which the plasma torch (10) is introduced into the cylinder.

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