DE102017213359A1 - Coating lance head, coating lance and masking plate for thermal coating, and a corresponding coating system and method - Google Patents

Abstract

In order to provide a coating lance head (100) or a coating lance (200) for thermally coating a metallic surface (10), it is proposed that between the insertion direction (16) of the holding lance (15) and the center axis alignment (17) of the hot gas jet (12). an included beam angle (18) is formed, which is smaller than 90 °. In order to further provide a masking shield (300) for shielding predetermined surfaces of an object (22) in a thermal coating, it is proposed that the top (25) to the axial extent (27) of the through-hole (26) has an included opening angle (28 ), which is greater than 75 ° and the upper side (25) at least in the region of the passage opening (26) has an anti-adhesion property. In addition, a corresponding coating system (400) and methods are proposed.

Description

The invention relates to a coating lance head according to the preamble of claim 1 and a coating lance according to the preamble of claim 3 for the thermal coating of a metallic surface. Furthermore, the invention relates to a masking shield for shielding predetermined surfaces of an object in a thermal coating according to the preamble of claim 4. Furthermore, the invention relates to a coating system and a method for thermally coating a metallic interior surface of an object according to the preamble of claim 10.

Technical area

Thermal coating is a process associated with thermal spraying. These include, but are not limited to, powder plasma spraying processes, such as atmospheric plasma spraying (APS), and wire-plasma spraying techniques, such as plasma transfer wire-arc (PTWA), rotating single-wire. Spraying (RSW). In addition, there are other relevant thermal coating processes such as arc wire spraying (LDS) and high-speed flame spraying (HVOF). These differ in principle by the provision of the cold, that is in the solid state, coating material as a powder (APS) or as a wire (RSW) or rod. In the wire-spray method, the coating material must be completely melted in order to be able to be separated from the feed material and thus accelerated as a particle against the surface to be coated. By contrast, in the case of the powder-spray method, it is possible, but not mandatory, merely to melt the individual powder particles and to obtain a cold, that is to say solid, core. In addition, in the powder-spray method, the shape and size or even a composition of the particles are freely adjustable. In the case of powder plasma spraying, the particles are generally melted in a plasma jet of up to 15,000 K, accelerated through the plasma gas and onto the workpiece to be coated or coated. applied to the surface to be coated. In this case, the energy of the particles / particles is set via the spray distance or plasma parameters so that the particles are just in liquid or. doughy state hit the surface, with the impulse impart their energy to the base material and solidify directly. A disadvantage is a dependence of the orientation and the scattering angle or the scattering cone of the coating effective cone beam of the material, size and shape of the supplied particles, and the feed direction and feed rate.

Each of the methods of thermal coating or plasma jet coating has in common that a hot gas jet containing at least partly ionized gas, for example a flame, is arranged both for heating the supplied material and for directionally accelerating the particles. Here, a cathode and anode is usually provided, between which an arc for ionization and / or ignition of a cold or preheated gas is generated. Alternatively, a gas with a desired temperature is supplied hot. In the wire spraying method PTWA, RSW, the supplied wire serves as an anode, so that an arc is used here between the cathode (torch) and anodically switched wire for melting the wire. In the LDS method (two-wire method), an arc is ignited between an anodic and a cathodically switched wire and the two wires are melted. In all wire methods, a nebulizer gas (compressed air or inert gas such as argon or nitrogen) is used to atomize and accelerate the injection molding material to be coated. The thermal coating differs from cladding mainly in that the heat input into the surface to be coated is at least so low that it is not melted, or is usually so low that the structure of the material to be coated is not changed.

State of the art

Such a coating lance and such a masking shield are made, for example WO 2016/015922 A1 , which deals with a device and a method for metallic coating and a receiving unit for this device, for example on page 2 , first to third paragraphs, known. There, the problem is described that when switching on and off of a metal plasma jet amplified overspray is generated and layer thickness deviations can occur on the workpiece. Like page 3 Therefore, the last paragraph indicates that the metal plasma jet should therefore not be switched off or switched on outside the surface to be coated and switched off.

Overspray is sometimes referred to as the pure dust content, which therefore merely leads to contamination by passive adhesion, for example due to static charge or molecular binding to freshly applied still fused coating material. Mainly, however, is material that is sprayed when dipping from the coating area (for example, a cylinder liner) in areas where no coating should or should adhere, such as Crankcase, top deck (water chambers, oil passages and the like) or material spewed freely into the room (for example, when immersing and dehumidifying the burner in and out of the cylinder tube between the individual coating overflows to the reversal points outside the cylinder tube or when transferring the burner into next cylinder bore or the next area to be coated) referred to as overspray. In addition, the proportion of the coating-effective cone beam is also referred to as overspray, which leads to an undesirably rough surface coating due to the reduced particle fraction in this jacket edge region. In the following, the last definition is used and the narrower first definition is called dust.

It will be in the WO 2016/015922 A1 in the last paragraph of the page 3 proposed for this purpose, to provide a suction bell, in which an annular receiving unit or a drum-shaped receiving unit is formed for attaching metal particles. This recording unit must be indicated on page 3 , third paragraph due to the addition regularly be changed. Furthermore, it is on page 10 , second paragraph, including the 4 described that a masking shield consisting of an annular flange 42 with a cone surface 44 is provided with respect to the support surface of the workpiece about 30 °, for deflecting thereon impinging metal particles towards the drum-shaped receiving unit 50 is set up so that the metal particles come there to the desired adhesion. To avoid adhesion to the conical surface, this is provided with a non-specified non-stick property. According to 3 and 4 is the cone surface 44 with a gap adjacent to a lower edge element 58 and to this according to first paragraph on page 10 for axially accurate, flexible placement on a workpiece arranged relatively movable resiliently. According to page 11 , first paragraph represents the boundary element 58 Make sure that metal particles do not come down from the receiving unit 50 escape.

From the EP 1 141 438 B1 For example, those skilled in the art who are concerned with an auxiliary device for thermally coating surfaces of an interior, will take the column from the person skilled in the art 13 Paragraph [0041] that adherence of coating material applied above the coating space to be coated is required to be performed on a wear sleeve, so as to surely avoid overspray particles from getting into the cylinder bore without melting. This would lead to irregularities and defects of the coating to be achieved. For this purpose, the wear sleeve is proposed 116 which according to 6 in operation directly adjacent to the cylinder crankcase shown there, to equip with particularly good adhesive properties.

Object of the invention

The object of the invention is to guide the coating jet in the case of a coating lance of the type mentioned at the beginning in such a way that an accumulation of particles of the coating jet on a masking shield is largely avoided. This is achieved by the fact that during operation of the coating lance and while the coating lance is in a non-coating position, ie outside of the area to be coated, the coating jet does not strike a counterface up to a beam end or at a shallow angle of less than 10 ° hits a counter surface.

Solution of the task

This object is achieved by the features specified in claim 1 and in claim 3, namely by an enclosed beam angle is formed between the insertion of the holding lance and the center axis alignment of the hot gas jet, which is smaller than 90 °.

Alternatively achieved or further favors the achievement of this goal by means of a masking shield by the features specified in claim 4, namely, by the masking shield has an upper surface which forms an enclosed opening angle to the axial extent of the passage opening, which is greater than 80 °.

Advantageous embodiments of the invention are characterized in the subclaims.

Description of the invention

• - Plasmadüse zum Erzeugen eines Heißgasstrahls, wobei der Heißgasstrahl eine vorbestimmbare Temperatur, Geschwindigkeit und Mittelachsenausrichtung aufweist;
• - Zuführeinrichtung zum Zuführen von Beschichtungsmaterial in fester Phase hin zu dem Heißgasstrahl; und
• - Winkelhalterung zum Befestigen des Beschichtungslanzenkopfs an einer Haltelanze, wobei die Haltelanze eine Einführrichtung aufweist,

wobei mittels der Winkelhalterung im mit der Haltelanze verbundenen Zustand zwischen der Einführrichtung der Haltelanze und der Mittelachsenausrichtung des Heißgasstrahls ein zu der Haltelanze hingeneigter eingeschlossener Strahlwinkel gebildet ist, welcher kleiner als 90° ist.According to a first embodiment of the invention, a coating lance head for thermal coating of a metallic surface is proposed, which has at least the following elements:

• - Plasma nozzle for generating a hot gas jet, wherein the hot gas jet has a predeterminable temperature, speed and center axis alignment;
• Feeding means for feeding solid phase coating material toward the hot gas jet; and
• Angle holder for fastening the coating lance head to a holding lance, the holding lance having an insertion direction,

wherein by means of the angle bracket in the state connected to the holding lance between the Insertion direction of the holding lance and the center axis orientation of the hot gas jet is formed a trapped to the holding lance enclosed jet angle, which is smaller than 90 °.

The coating lance head is a separate component that is adapted for connection to a holding lance. For this purpose, the coating lance head has connections for the supply of the coating jet, such as a gas connection for the gas (mixture) of the hot gas jet, a coating material connection, connections for cooling and jacket gases (for example compressed air or inert gases), an electrical connection and possibly one or more coolant connections. Furthermore, the coating lance head preferably has one or more sensors and / or one or more connections for a detection device, which makes it possible to monitor at least one process parameter.

The coating lance head has a plasma nozzle, which is set up for aligning and accelerating the hot gas jet. The plasma nozzle can be supplied via a corresponding gas connection with gas (mixture) for the hot gas jet. Furthermore, the plasma nozzle is often designed to generate an arc as the anode and / or cathode. The plasma nozzle is designed for the pure transport of gas or for the transport of a gas (mixture) already equipped with particles. The shape and type of the plasma nozzle can be seen by those skilled in the well-known prior art. From the type and shape of the plasma nozzle results in addition to the shape and velocity of the hot gas jet, the center axis orientation of the hot gas jet. As a rule, this is the extension of the central axis of a rotationally symmetrical plasma nozzle.

The supply device included in the coating lance head can be charged with a suitable coating material via a coating material connection, so that the coating material can be fed to the hot gas jet at the desired speed and orientation. For example, results from a desired orientation of the feeder, a feed direction at a right angle, that is about 90 ° to the center axis orientation of the hot gas jet. Suitable materials are not only metals but also ceramics or ceramic-metal mixtures or rather friction-reducing components such as molybdenum sulfide (MoS ₂ ) or the like containing metal mixtures. The coating material is provided in powder form, rod-shaped or wire-shaped and melted by the hot gas jet or merely fused. In a generally lateral feed, for example transversely to the central axis orientation, of a powdered coating material, in many process guides, the cone beam of the coating material deviates from the hot gas jet and / or inclined to the center axis orientation of the hot gas jet; away from the outlet of the feeder. These parameters can also be deduced by the person skilled in the art from the generally known state of the art and, if appropriate, adjusted reproducibly by manageable tests.

The coating lance head also has an angle holder, via which the angular position of the center axis alignment of the hot gas jet, as defined by the respectively used plasma nozzle, is fixed to the insertion direction of a holding lance or is freely adjustable. Preferably, the angle bracket comprises the above-mentioned connections. Independently of this, in one embodiment, the angle holder has a connection surface which is aligned transversely to the insertion direction of the holding lance and can be connected to a correspondingly formed mating connection surface, preferably detachably. The person skilled in the art understands that the shape and inclination of the angle holder can be selected freely and must be matched only to a correspondingly formed mating connection surface for setting or adjusting the desired angular position of the center axis alignment of the hot gas jet. The connections of the type described above with respect to the coating lance head are preferably provided in the corresponding connection surface and mating connection surface, and particularly preferably the connections of the coating lance head and the corresponding mating connections of the holding lance can be connected directly to one another when fastening together. In one embodiment, for example for use with liquid media, at least one check valve or at least one self-closing line is used.

The insertion of the holding lance and thus the coating lance head in operation is in many applications, especially when coating an interior surface, such as a cylinder bore in a cylinder crankcase of an internal combustion engine, and other cramped conditions, congruent with the axial straight extension of the holding lance. However, it may be advantageous for other applications to use the holding lance in a free form. The direction of insertion is the direction of movement required for a desired coating result. Under certain circumstances, the trajectory of such a direction of movement deviates from a straight line.

Between the insertion direction and the center axis alignment of the hot gas jet is in use by means of the angle bracket, a beam angle of less than 90 ° before, preferably less than 80 °, more preferably of less than 70 ° before. Preferably, the orientation of the feed device is correspondingly inclined, so that, for example, an angle of approximately 90 ° between the center axis orientation and the feed direction is established. The choice of the beam angle is preferably to be selected by the type and inclination of a shielding top of a masking shield, so that the coating beam does not hit a counter surface up to a beam end in a non-coating position or strikes a counter surface at a shallow angle of less than 10 ° , The beam end is an end of the cone beam, from which the cone beam is no longer effective in coating in the beam direction.

In a cylinder crankcase, a non-coating position of the coating jet is, for example, a position in the extension of the rotational axis of a cylinder bore to be coated, in which the coating jet is not directed to a wall of the cylinder bore. Due to the conical fan of the coating jet, this condition of impingement on a mating surface also applies in a position in which a part of the coating jet is still directed to the wall of the cylinder bore and another part is already applied outside the cylinder bore. The steeper the beam angle is selected, the steeper a shielding top side of a masking shield can be provided and / or the lower the radial dimension of the masking shield can be interpreted, because the radial extent of the coating beam is smaller up to the beam end.

According to an advantageous embodiment of the coating lance head, the supplied coating material forms a coating-effective cone beam in the coating operation due to the acceleration by means of the hot gas jet, and between the maximum inclined from the insertion of the holding lance mantle line of the cone beam and the insertion of the holding lance an enclosed maximum angle is formed, which is equal or smaller 90 ° is.

The coating operation is the state in which a stable coating-effective cone jet is generated by means of the hot gas jet and the coating material. This is independent of whether a surface is coated or the cone beam is applied away from a surface to be coated.

The coating-effective conical jet is the proportion of the coating material accelerated by means of the hot gas jet, which can produce a desired coating or tolerated tolerances of the surface to be coated: The coating-effective cone jet has approximately a conical shape, the gravitational and / or due to the material supply a radiating side Ellipse may have base as base and / or an inclined cone height. The cone height of the cone beam can be offset and / or inclined away from the center axis alignment of the hot gas jet. This is usually the case in a powder-injection process when the powder is fed laterally to the hot gas jet. The coating-effective cone beam is bounded by a lateral surface. For example, the exact position of the lateral surface can be deduced by considering the deposit image of a punctiform or one or more linear coatings. Alternatively, lateral images can provide information. The person skilled in the art can refer to extensive well-known prior art in the determination.

The generatrix, which is the most inclined away from the insertion direction, forms with the insertion direction the included maximum angle. In a vertical orientation of the insertion, the maximum flattened surface line is at a pivoting of the cone beam from above, as the side of the holding lance, to the horizontal below the cone height, and at least when the coating-effective cone beam forms a circular cone, within the of the insertion direction and the cone height spanned level. In the case of a coating-effective cone beam with an elliptical base surface rotated around the cone height with respect to this plane, the maximum angle is formed by the surface line lying in the plane in which the generatrix which slopes farthest downward from the insertion direction lies. The coating-effective cone beam thus has no line, which is further inclined away from the insertion direction than the surface line, which includes the maximum angle with the insertion direction.

In use by means of the angle bracket, a maximum angle of 90 ° or less, preferably less than 80 °, particularly preferably less than 70 °, is present between the insertion direction and the maximum away-inclined surface line. The choice of the maximum angle is preferably to be selected by the type and inclination of a shielding top of a masking shield, so that the coating effective cone beam does not hit a counter surface up to a beam end in a non-coating position or with a shallow angle of less than 10 ° on a counter surface meets.

In this embodiment, adherence of particles to an inclined shielding top of a masking shield is almost impossible or at least to the proportion of the Reduces coating effective cone beam, which strikes an opposing surface with an angle of more than 10 °.

Preferably, a deposit is also reduced by a suitable suction or air duct.

• - Atmosphärisches Plasmaspritzen (APS);
• - Rotating-Single-Wire-Spritzen (RSW);
• - Plasma-Transfer-Wire-Arc-Spritzen (PTWA);
• - Lichtbogen-Draht-Spritzen (LDS);
• - Hochgeschwindigkeitsflammspritzen (HVOF); und
• - Flammspritzen

The coating lance head is preferably set up for one of the following processes:

• - Atmospheric plasma spraying (APS);
• - Rotating Single Wire Injection (RSW);
• Plasma Transfer Wire Arc Injection (PTWA);
• - arc wire spraying (LDS);
• - high velocity flame spraying (HVOF); and
• - flame spraying

Atmospheric plasma spraying (APS) is a process in which a powder in the solid state is supplied to an ionized hot gas jet, for example a flame, laterally, partly also with several injections, from behind, from above and / or from below , In addition to the advantages of a highly variable and cost-effective process control, as described above, this powder-based method has the characteristic of a large opening angle of the coating-effective cone beam. Therefore, coating effective particles of a conventional coating lance in a position extended out of an interior to be coated meet also at a shallow opening angle of a conventional through hole of a masking shield at a relatively steep angle. As a result, these particles can adhere to this conventional passage opening or, as dust particles, return to the area of the surface to be coated as a result of the opening angle. There they can be embedded in the ongoing coating process in the applied layer and thus lead to large defects and thus rejects. Even in subsequent washing processes, these can no longer be solved or not without damage. Thus, the surface no longer meets the desired properties, especially not for a reduced friction. Thus, the prevailing opinion until now was that atmospheric plasma spraying alone with a sacrificial ring with good adhesive properties following the surface directly to be coated in the insertion direction could be used. However, with the negative angling of the center axis orientation of the hot gas jet or even the maximum angle of the coating effective cone jet, a solution without adhesion and without the danger of dust adhering to the area of a workpiece to be coated is found. The non-stick properties of the masking shield need not be optimal in order to minimize the adhesion of overspray. Thus, the device is very inexpensive executable. These advantages can also be utilized for the wire-spray method, in that steeper angles of the through-opening and / or a more cost-effective non-stick material can be used there.

• - Plasmadüse zum Erzeugen eines Heißgasstrahls, wobei der Heißgasstrahl eine vorbestimmbare Temperatur, Geschwindigkeit und Mittelachsenausrichtung aufweist;
• - Zuführeinrichtung zum Zuführen von Beschichtungsmaterial in fester Phase hin zu dem Heißgasstrahl;
• - Haltelanze, wobei die Haltelanze eine Einführrichtung aufweist,

wobei zwischen der Einführrichtung der Haltelanze und der Mittelachsenausrichtung des Heißgasstrahls ein zu der Haltelanze hin geneigter eingeschlossener Strahlwinkel gebildet ist, welcher kleiner als 90° ist.According to a further aspect of the invention, a coating lance for thermal coating of a metallic surface is proposed, which has at least the following elements:

• - Plasma nozzle for generating a hot gas jet, wherein the hot gas jet has a predeterminable temperature, speed and center axis alignment;
• Feeding means for feeding solid phase coating material toward the hot gas jet;
• Holding lance, wherein the holding lance has an insertion direction,

wherein between the insertion direction of the holding lance and the center axis alignment of the hot gas jet is formed an inclined beam angle inclined to the holding lance, which is smaller than 90 °.

The coating lance has lines for supplying a coating jet, such as a gas line for the gas (mixture) of the hot gas jet, lines for cooling and jacket gases (for example compressed air or inert gases), a coating material line, an electrical line and optionally one or several coolant lines. Furthermore, the coating lance preferably has one or more sensors and / or one or more connections for a detection device, whereby it is possible to monitor at least one process parameter.

The coating lance has a plasma nozzle, which is set up for aligning and accelerating the hot gas jet. The plasma nozzle can be supplied via a corresponding gas line with gas (mixture) for the hot gas jet. Furthermore, the plasma nozzle is often designed to generate an arc as the anode and / or cathode. The plasma nozzle is arranged as described above with respect to the coating lance head, and to that extent reference is made to the above description.

The feeding device included in the coating lance can be charged with suitable coating material via a coating material line so that the coating material can be fed to the desired speed and orientation Hot gas jet can be supplied. Suitable materials and orientation of the feeder are set forth above with respect to the coating lance head, and to that extent reference is made to the above description.

The coating lance comprises a holding lance which is adapted to keep the plasma nozzle and the feeder exactly aligned during a coating movement. In addition, the holding lance comprises the main part of the above-described lines and optionally the sensors and / or connections described above.

The insertion of the holding lance and thus the coating lance in operation is congruent with the axial straight extension of the holding lance in many applications, especially when coating an interior surface, such as a cylinder bore in a cylinder crankcase of an internal combustion engine, and other cramped conditions. However, it may be advantageous for other applications to use the holding lance in a free form. The direction of insertion is the direction of movement required for a desired coating result. Under certain circumstances, the trajectory of such a direction of movement may deviate from a straight line.

The coating lance is set up such that the angular position of the center axis orientation of the hot gas jet, as defined by the respectively used plasma nozzle, is fixed to the insertion direction of a holding lance or is freely adjustable.

In use, a jet angle of less than 90 °, preferably less than 80 °, particularly preferably less than 70 °, is present between the introduction direction and the center axis alignment of the hot gas jet. The beam angle and the feeding direction are set as above with respect to the coating lance head, and to that extent reference is made to the above description.

According to an advantageous embodiment of the coating lance formed in the coating operation, the supplied coating material due to the acceleration by means of the hot gas jet, a coating effective cone beam, and between the maximum of the insertion of the holding lantern inclined cantilever line of the cone beam and the insertion of the holding lance an enclosed maximum angle is formed, which is equal or smaller 90 ° is.

The features mentioned in the previous paragraph are described above with respect to the coating lance head and to that extent reference is made to the above description.

• - Atmosphärisches Plasmaspritzen (APS);
• - Rotating-Single-Wire-Spritzen (RSW);
• - Plasma-Transfer-Wire-Arc-Spritzen (PTWA);
• - Lichtbogen-Draht-Spritzen (LDS);
• - Hochgeschwindigkeitsflammspritzen (HVOF); und
• - Flammspritzen

The coating lance is preferably set up for one of the following processes:

• - Atmospheric plasma spraying (APS);
• - Rotating Single Wire Injection (RSW);
• Plasma Transfer Wire Arc Injection (PTWA);
• - arc wire spraying (LDS);
• - high velocity flame spraying (HVOF); and
• - flame spraying

The methods mentioned in the previous paragraph are described at the outset and continue with reference to the coating lance head, and to that extent reference is made to the above description.

According to an advantageous embodiment of the coating lance, the plasma nozzle and the feed device are arranged in a coating lance head as described above.

In one embodiment, the angle holder has a connection surface, which is aligned transversely to the insertion direction of the holding lance and can be connected to a correspondingly formed mating connection surface of the holding lance, preferably detachably. The skilled person understands that the shape and inclination of the angle bracket is arbitrary and must be adapted only to a correspondingly formed mating connection surface for setting or adjustability of the desired angular position of the center axis alignment of the hot gas jet. The connections of the type described above with respect to the coating lance head are preferably provided in the corresponding connection surface and mating connection surface, and particularly preferably the connections of the coating lance head and the corresponding mating connections of the holding lance can be connected directly to one another when fastening together.

• - Unterseite zur Auflage auf einer abzuschirmenden Oberfläche;
• - Oberseite, welche einer Beschichtungslanze zugewandt ist, wenn sich die Beschichtungslanze in einer herausgefahrenen Position befindet;
• - Durchgangsöffnung mit einer axialen Erstreckung von der Oberseite zu der Unterseite, durch welche eine Beschichtungslanze hindurchtauchbar ist, um das Objekt zu beschichten, wobei die Oberseite zu der axialen Erstreckung der Durchgangsöffnung einen eingeschlossenen Öffnungswinkel bildet, welcher größer als 75° ist;
• - Anti-Haftbeschichtung auf der Oberseite und ggf. auf der Unterseite im Bereich der Öffnung.

According to a further aspect of the invention, a masking shield is proposed for shielding predetermined surfaces of an object in a thermal coating, comprising at least the following elements:

• - Bottom to rest on a surface to be shielded;
• - Top, which faces a coating lance, when the coating lance is in a retracted position;
• - Through opening with an axial extent from the top to the bottom, through which a coating lance is submersible to coat the object, the top to the axial extent of the passage opening forms an included opening angle which is greater than 75 °;
• - Anti-adhesive coating on the top and possibly on the bottom in the area of the opening.

In a preferred embodiment, the upper side radially adjoins gap-free outer walls, wherein the outer area slopes away from the upper side and runs parallel to the lower side or tilts towards the lower side.

For example, the top has no kink and is thus formed as a continuous surface. In a preferred embodiment, the upper side has one or more kinks, so that the upper side is subdivided into a plurality of partial surfaces each having a different angle. The opening angle is that of the directly adjacent to the passage opening or the total slope of the partial surfaces, up to the transition to the next partial surface or the outer region, the coating-effective cone beam extends to its radiant end.

The upper side, and preferably also the lower side, has an anti-adhesion property at least in a partial area adjacent to the through-opening, so that, as a result of the pairing of materials from the upper side and the particles, adhesion is hindered or even prevented. The portion extends radially at least to the radiant end of the cone beam.

In a preferred embodiment, the non-stick property is achieved by providing the top surface with a non-stick coating. As a result, adhesion of spray particles and dust particles is difficult or impossible. The flat angle of the upper side proposed here also has the advantage that particles lying on the upper side can not or at least do not easily reach the region of the surface to be coated with the disadvantages mentioned above, but rather remain lying or even impulse of the Hot gas jet following radially outward, ie upwards, move.

In a further preferred embodiment, the underside is provided with a non-stick coating, at least in the region of the passage opening, for example over an edge of at least 1 cm, or over the entire contact surface. As a result, adherence of particles that are unlikely to get into the gap between shielding surface and masking shield prevented.

The masking shield differs from the prior art in that a sacrificial ring is superfluous because adhesion of coating material and damage to the areas to be coated or just coated can be precluded by dust or overspray reaching into these areas. This is also advantageous for a powder-spray process, such as atmospheric powder spraying (APS).

The underside of the masking shield is adapted to rest on a surface to be protected, for example, a Topdeckfläche a cylinder crankcase, in which openings are provided for a water chamber and oil spills under certain circumstances.

The upper side faces a coating lance, so that the upper side can be partially struck by coating-effective particles in a state in which a coating jet is not completely directed onto a surface to be coated. This condition is referred to here as a submerged position.

Through the masking shield extends a passage opening, which thus pierces the top and bottom. This is on the one hand intended to form a passage for the coating lance. On the other hand, the passage opening forms a template with which, for example, a precisely defined edge area around the entrance to the surface of the object to be coated is left free. As a result, this edge region is also coated. This coated edge area leads to an edge coating. This edge coating favors the mechanical strength of the coating in the interior compared to a chamfer, which usually follows the coating process directly or indirectly in a post-processing of a cylinder crankcase. This edge region is to be set up in such a way that it is completely removed by the bevelling, for example by the milling tool. On the other hand, the edge area must not be too narrow or too irregular, because otherwise sufficient mechanical strength is not achieved and the remaining coating in the interior can be damaged. Alternatively, the diameter of the passage opening is exactly equal to or smaller than the diameter of the cylinder to be coated.

Maskings are known from the prior art, which have a sacrificial ring, which is axially adjacent directly to the surface to be shielded. This sacrificial ring has explicitly good adhesion properties for the coating material in order to prevent dust falling into the interior to be coated and thus damage. Due to the narrow margin between maximum edge width and minimum edge width and also the reduction of adhesive properties by sacrificial coating such sacrificial rings must be replaced very often, for example, after one to six coating operations.

A solution for this is mentioned in the beginning WO 2014/015922 A1 described. However, a recording drum to be coated is still to be used. In addition, the proposed opening angle of 60 ° at the through-hole is not favorable for all spray methods, and in particular is not suitable for a powder-spray method. Rather, it comes to deposits and embedding of dust in the coating.

The axial extension of the passage opening is preferably a perpendicular to the plane spanned by the underside. For deviating geometries of the object to be coated, it may be deviated accordingly. In a coating of the running surface of a cylinder crankcase, the axial extent in operation is preferably congruent to the axis of rotation of a cylinder bore.

Here it is now proposed to provide an opening angle of greater than 75 °, preferably greater than 85 °, enclosed to the axial extension of the passage opening. In order to keep a masking shield as narrow as possible, and thereby obtain short delivery routes, it is generally not advantageous to provide a shallower angle than 90 °, ie a negative slope towards the bottom. In addition, it is advantageous to use the masking shield in conjunction with an exhaust, ie negative pressure, or an air duct, so a directed compressed air supply. In this case, the resulting dust should be led away from the interior to be coated, advantageously therefore at an angle smaller than 90 °.

In a powder injection method, for example atmospheric powder spraying (APS), it is advantageous to provide a particularly flat opening angle of 85 ° to 88 °. As a result, the probability or frequency of adhesion can be reduced, thereby increasing the service life of the masking shield.

In one embodiment, the masking plate is plate-shaped and extends at least as far as the coating-effective cone beam extends to its radiant end. As a result, adherence of coating-effective particles to surfaces to be shielded of the object to be coated is avoided.

In a particularly preferred embodiment, the masking shield is designed asymmetrically and covers the entire surface to be shielded and / or the surfaces not yet to be coated or already coated at the time of the concrete treatment. It must be ensured that the surfaces to be coated or already coated are still extractable, for example in the case of a cylinder crankcase from the crankcase. For this purpose, the masking shield is arranged for a subsequent flow or outflow of air to or from the surfaces to be coated or already coated.

For some applications, it is advantageous to provide a chamfer between the top to the bottom, wherein the chamfer has a steep contact angle. As a result, a clean-limited coating of the folded edge is favored in an interior coating. When the masking shield is raised following the coating process, the coating material adheres to the surface to be coated due to the cohesive effect and dissolves without residue from the masking shield. This chamfer has an anti-sticking property, as described above with respect to the top, preferably by using the same material or the same coating.

• Polytetrafluorethylen (PTFE);
• oder Verbindungen, enthaltend zumindest eines der folgenden Materialien:
  • - diamantartigen Kohlestoff [DLC];
  • - Silizium-DLC [Si-DLC]
  • - Metall-DLC
  • - tetraedrische wasserstofffreie amorphe Kohlenstoffschicht [ta-C]
  • - diamantähnliche Kohlenstoffschichten
  • - Titan-Nitrid [TiN];
  • - Titan-Bor-Nitrid [TiBN];
  • - Titanborid [TiB₂];
  • - Titan-Aluminium-Nitrid [TiAIN]
  • - Chrom-Nitrid [Cr₂N]
• oder Legierungen, mit folgendem Hauptbestandteil:
  • - Kupfer;
  • - Messing;
  • - Bronze.

The masking shield is at least at a transition from the through-hole, and preferably in the entire region of the top, unsuitable for adhering by hot gas jet applied coating material. It preferably has a surface on or is formed from solid material, consisting of:

• Polytetrafluoroethylene (PTFE);
• or compounds containing at least one of the following materials:
  • diamond-like carbon [DLC];
  • - Silicon DLC [Si-DLC]
  • - Metal DLC
  • - tetrahedral hydrogen-free amorphous carbon layer [ta-C]
  • - diamond-like carbon layers
  • Titanium nitride [TiN];
  • Titanium boron nitride [TiBN];
  • Titanium boride [TiB ₂ ];
  • - Titanium Aluminum Nitride [TiAIN]
  • - chromium nitride [Cr ₂ N]
• or alloys, with the following main constituent:
  • - Copper;
  • - Brass;
  • - Bronze.

The choice of suitable material depends on the desired service life, the selected opening angle and the coating process. From the prior art, it is known to the person skilled in the art which materials have better or poorer adhesive properties for the respective plasma spray method. In particular, in combination with the bevel for a steep contact angle at the transition of the top to the through hole temperature-stable diamond-like carbon layers, (DLC) silicon DLC [Si-DLC] or metal DLC layers are advantageous, with a particularly low adhesion is achieved. A suitable material should have the following properties: In addition to the specified non-stick properties, it should form a scratch-resistant and abrasion-resistant surface, be thermally stable up to 500 ° C and have a suitable chemical resistance.

If the masking shield has an intermediate surface, for example a chamfer, between the top side and the bottom side, then according to this embodiment it is designed with the abovementioned non-stick properties. For a further improvement of the service life is also a corresponding non-stick property of the top, preferably the entire top with the opening angle provided. For some applications, it is cheaper to use different materials or coatings, because the probability of impact of coating-effective particles is geometrically different sizes. For example, in a high impact probability region, a material with poor adhesion properties, such as PTFE, diamond-like carbon (DLC) layers, silicon DLC (Si-DLC) layers or metal DLC layers, and in another lower likelihood region should have a material with possibly better adhesion Attachment property, such as bronze, are used. This is to be selected according to desired service life and costs of materials and production.

According to an advantageous embodiment of the masking shield, the upper side extends with the opening angle up to the passage opening.

Here it is proposed that the upper side with the flat opening angle directly to the underside, so in operation the shielded surface of the object to be coated, to be adjacent. This ensures that the masking shield has no partial surface that could be subject to increased adhesion.

According to an advantageous embodiment of the masking shield, the underside has a stepped region, which has a low roughness and high flatness, preferably polished.

For a simple and well-sealing installation of the masking shield on the surface to be shielded, it is desirable to make the underside particularly smooth. Laying on an equally smooth surface to be screened then leads to a secure shielding at the gap between the masking shield and the object to be coated, through which no coating-effective particles and no or hardly any dust can penetrate.

However, such a surface is expensive to manufacture. Therefore, it is proposed here to design the area of the support, that is to say the contact-effective underside, as small as possible and to execute it just so far that the passage opening is enclosed circumferentially. This is a Dichtumringung formed. In addition, it is advantageous to provide stabilizing surfaces and / or struts of the sealing ring radially outward. This favors, for example, a defined smooth seating. As a result, the opening angle of the upper side is kept in shape in a particularly thin design.

According to a further aspect of the invention, a coating system for thermally coating a metallic interior surface is proposed which comprises a coating lance and a masking shield, preferably as described above. The portion of the conical jet discharged above the upper side in the coating operation of the coating lance is oriented at a flat discharge angle to the upper side, wherein the discharge angle between the portion of the conical jet and the upper side is less than 10 ° or negative, preferably between 5 ° and -45 °.

The coating system comprises a prior art coating lance together with a masking shield according to the above description or vice versa a coating lance as described above and a prior art masking shield or a combination of prior art masking shield and prior art coating lance so that in each case the discharge angle is less than 10 °. Alternatively, both system components are implemented as described above. Also in an embodiment with elements of the state The technique is referred to the above definitions.

The coating lance is designed for immersion in an interior space, for example a cylinder bore of a cylinder crankcase. The coating lance should be started in the outside of the interior to be coated and produce a stable coating effective cone beam before the cone beam is directed to a surface to be coated. Similarly, the cone beam should be switched off after a coating only outside the interior again. The metallic interior surface is, for example, an aluminum surface, which has preferably been previously roughened, for example by means of sandblasting.

The respective angle, ie the center axis orientation or the maximum angle and the opening angle respectively, are to be adjusted accordingly. In this way, adhesion of coating-effective particles to the masking shield is avoided or at least reduced to the extent that the service life of the masking shield is multiplied, for example, from currently one manual replacement of the sacrificial ring after one to six shifts to one to six months. The service life is based on the entire masking shield or at least the upper side with the opening angle, the other constituents of the masking shield having just as long or longer service lives.

Preferably, the masking shield and the coating lance are guided together and can be jointly guided by the surface to be coated to be coated surface or they are each fed to the coating system. In this case, the coating lance along its insertion direction is at least then axially movable relative to the masking shield when the masking shield is placed sealingly on a surface to be shielded.

The area above the top is the area in which a surface normal shows the top.

The portion of the conical jet which is spread above the top is the entire portion which is not to be adhered to the surface to be coated. A share for an optionally to be produced edge coating is therefore not designated, even if it is removed in a later process step again. Rather, in the coating process considered here, this is to be regarded as a surface to be coated.

The discharge angle is the angle between any proportion of the above the top of the applied portion of the cone beam and the top with the opening angle. Along this Abführwinkels a removal of the discharged particles is possible without adhesion. This is favored by a suction and / or air duct, preferably parallel to the top.

The discharge angle is 0 ° in the case of a parallel discharge of a portion of the cone beam. If the portion of the cone beam is tilted away from the top of the masking shield, the discharge angle is negative. The maximum tilted discharge angle is determined by the technically meaningful for the coating minimum angle of the coating effective cone beam. The minimum angle is the angle, which is opposite the maximum angle defined above, in the lateral surface of the coating-effective cone beam. The maximum fan of the coating-effective cone beam is thus spanned by the minimum angle and the maximum angle. The maximum weggeneigte discharge angle is therefore less than (minus) 60 °, preferably below (minus) 45 °. The maximum inclined discharge angle is a maximum of 10 °, preferably less than 5 °.

According to a further aspect of the invention, a process box for thermal coating of a metallic interior surface is proposed, which has at least one coating system as described above, wherein the at least one coating system is integrated into a closed, suctionable housing, wherein the coating-effective cone beam in the beam direction Having radiating, behind which the cone beam is no longer coating effect, and the coating effective cone beam can hit up to the beam end only on the top of the masking shield or on an unsuitable for adhesion surface.

The process box forms a space with a volume which is opened solely by means of the passage opening and air discharge means. Construction-related column are not considered here. Thus, the dust generated by the continuously operated cone jet is collected in the process box, as far as it is not discharged through a rear side of the interior. For example, in a cylinder crankcase, the backside is the crankcase. The volume of such a process box is therefore small compared to a coating in an open space. At the same time, however, no sacrificial ring is necessary and no other precipitation in the process box is expected, which would require a service life of less than one month, preferably less than six months. In particular, it is not necessary to manually replace a component after one to two layers.

The dust-laden air in the process box is removed by a suction or air duct and fed to an external separator.

The through-opening of the process box is closable when the underside of the masking shield is lifted off the surface to be screened. Alternatively or additionally, a shielding device is provided, by means of which the object to be coated is protected from dust deposits in the region of the surfaces to be coated.

• - Zustellanlage zum ausgerichteten Zustellen zumindest eines Zylinderkurbelgehäuses, bevorzugt ein Drehtisch;
• - Prozessbox gemäß obiger Beschreibung, welche als eine Einheit auf zumindest ein zugestelltes Zylinderkurbelgehäuse mit der Unterseite des Maskierungsschilds dichtend absenkbar ist; und
• - Absauganlage zum Absaugen von in die Prozessbox ausgebrachtem Beschichtungsmaterial.

According to a further aspect of the invention, a coating installation for thermally coating a cylinder crankcase for an internal combustion engine is proposed, which has at least the following elements:

• - Delivery system for aligned delivery of at least one cylinder crankcase, preferably a turntable;
• - Process box according to the above description, which is sealingly lowerable as a unit on at least one delivered cylinder crankcase with the underside of the masking shield; and
• - Extraction system for suction of applied in the process box coating material.

The coating plant is equipped for fully automated thermal coating of the cylinder bores of a cylinder crankcase. In addition, a multi-axis robot is not necessary to replace or support human movement sequences. On the contrary, an applied to the feed system cylinder crankcase with one-axial movement of the processing position is supplied, for example by rotation of a turntable. Likewise, the process box with one-axial movement is placed on the spent in machining position cylinder crankcase, for example, lowered along a vertical line from above on the top deck of the cylinder crankcase. If appropriate, in addition, for example, for V-engines or W-motors a pivot axis transverse to the cylinder axes of the cylinder bores are provided so that the cylinder bores are vertically aligned. Regardless, a delivery means may be provided, whereby the cylinder bores in a row can be delivered to the coating system, or whereby the coating system can be delivered successively to the cylinder bores.

The extraction system is designed to remove and preferably filter out generated dust in the process box and at least parts in the cylinder bore. The extraction system is set up to generate a negative pressure in the process box and / or is supported in the process box by a compressed air guide.

1. a. Betreiben eines stabilen beschichtungswirksamen Kegelstrahls mittels eines Heißgasstrahls und einem Beschichtungsmaterial in einer herausgefahrenen Position, sodass eine zu beschichtende Innenraum-Oberfläche nicht, zumindest nicht beschichtungswirksam, von dem Kegelstrahl getroffen wird;
2. b. zeitgleich mit oder vor Schritt a., ausgerichtetes Aufsetzen eines Maskierungsschilds, bevorzugt gemäß obiger Beschreibung, auf eine abzuschirmende Oberfläche des Objekts, mit einer Durchgangsöffnung derart ausgerichtet, dass abzuschirmende Oberflächen des Objekts mittels des Maskierungsschilds in jeder axialen Betriebsposition des Kegelstrahls vor einem Beschichten geschützt sind und mittels der Durchgangsöffnung eine zu beschichtende Innenraum-Oberfläche für den Kegelstrahl zum Beschichten zugänglich ist;
3. c. anschließend nach Schritt a. und b., entlang einer Einführrichtung Eintauchen des beschichtungswirksamen Kegelstrahls in den Innenraum mit der zu beschichtenden Innenraum-Oberfläche, wobei der beschichtungswirksame Kegelstrahl eine von der Einführrichtung maximal weggeneigte Mantellinie aufweist, und wobei der durchgangsöffnungsseitige Auftreffwinkel zwischen der maximal weggeneigten Mantellinie und der zu beschichtenden Innenraum-Oberfläche gleich oder größer als 90° ist, bevorzugt größer als 95° ist.

According to a further aspect of the invention, a method is proposed for the thermal coating of an interior metal surface of an object, preferably by means of a coating lance as described above, which has at least the following steps:

1. a. Operating a stable coating-effective cone jet by means of a hot gas jet and a coating material in a deployed position so that an interior surface to be coated is not struck by the cone jet, at least not with coating effect;
2. b. coincident with or prior to step a., aligned placing a masking shield, preferably as described above, on a surface to be shielded of the object, aligned with a through hole so that surfaces to be shielded of the object are protected by the masking shield in any axial operating position of the cone beam from coating and by means of the passage opening to be coated interior surface for the cone beam for coating is accessible;
3. c. then after step a. and b., along an insertion direction, immersing the coating-effective cone beam in the interior space with the interior surface to be coated, the coating-effective cone beam having a generatrix line inclined maximally away from the insertion direction, and the passage opening side angle of incidence between the maximally inclined surface line and the interior to be coated Surface is equal to or greater than 90 °, preferably greater than 95 °.

The method described herein makes reference to the devices discussed above for coating an interior surface of an object, such as a cylinder bore of a cylinder crankcase. This is referred to accordingly. The method described here can also be taken from the rest of the description with reference to the devices further steps.

In step a. ensures that a cone beam is generated, with which a reliable coating quality can be generated. Turning on and off takes place outside the interior.

In step b. the masking shield is placed on the surface of the object to be screened so that the surface to be coated is exactly exposed. For example, in a cylinder crankcase, a cylinder bore is exposed by means of the passage opening, wherein preferably the passage opening to the upper edge of the cylinder bore is slightly spaced, so the diameter of the passage opening is slightly larger than the diameter of the cylinder bore. This ensures that an edge coating desired here is produced. But it can also be a through hole with a diameter of the cylinder bore or a smaller diameter than the cylinder bore can be used.

In step c. the coating lance is immersed in the interior and the interior surface is simply or repeatedly coated with well-known or expertly determined movement of the coating lance. A coating-effective cone jet is operated stably until the coating is complete. Only after the completed escape from the interior of the cone beam is turned off. For many applications, the cone beam for the multiple coating and / or multiple interiors in the evacuated, ie moved out of the interior, position, stable operation continues.

The angle of incidence, assuming an ideal straight generatrix after the jet set with parallel alignment of the insertion direction and the interior surface to be coated, is the supplement angle to the maximum angle defined above according to the above description with reference to the insertion direction. If, for example, the coating lance dips into an interior space along gravity, the angle of incidence corresponding to this orientation must be decreased from above the cone beam from the interior surface to be coated, and thus an angle greater than 90 °. For this purpose, reference is made to the above description with respect to the maximum angle.

The method described above is preferably integrated into a post-processing process with several stations. By way of example, the coating is preceded by corundum blasting or water jetting or laser beam roughening or mechanical roughening with a geometrically defined sheath, including a washing process, and a washing process then follows. The objects to be coated are preferably supplied automatically, with no need for manual manipulation or the use of a multi-axis robot replacing human movements.

list of figures

• 1 in einer schematischen Schnittdarstellung einen Beschichtungslanzenkopf an einer Haltelanze in einem zu beschichtenden Innenraum,
• 2 in einer räumlichen Ansicht ein Beschichtungssystem mit einem Maskierungsschild aufgelegt auf ein Zylinderkurbelgehäuse,
• 3 in einer Draufsicht eine bevorzugte Ausführungsform eines Maskierungsschilds,
• 4 in einer seitlichen Schnittansicht das Maskierungsschild gemäß 3,
• 5 in einer gleichen Schnittansicht wie in 4 eine weitere Ausführungsform eines Maskierungsschilds,
• 6 in einer schematischen Schnittansicht eine Beschichtungsanlage mit einer Prozessbox oberhalb einer Zustellanlage.

Embodiments of the invention are explained below with reference to the drawing. Show it

• 1 in a schematic sectional view of a coating lance head on a holding lance in an interior to be coated,
• 2 in a spatial view, a coating system with a masking shield placed on a cylinder crankcase,
• 3 in a plan view, a preferred embodiment of a masking shield,
• 4 in a side sectional view of the masking shield according to 3 .
• 5 in a same sectional view as in 4 another embodiment of a masking shield,
• 6 in a schematic sectional view of a coating system with a process box above a delivery system.

Best way to carry out the invention

In 1 is a fragmentary coating lance 200 with a coating lance head 100 shown in section. The coating lance head 100 is at a holding lance 15 by means of an angle bracket 14 fixed such that a center axis orientation 17 a hot gas jet 12 under one between an insertion direction 16 the holding lance 15 and the center axis alignment 17 included beam angle 18 is aligned by about 70 °. The insertion direction 16 Here is a parallel perpendicular to the axis of rotation 42 of the purely schematically illustrated interior 38 , For example, a cylinder bore of a cylinder crankcase, with a metallic surface to be coated 10 , for example, aluminum.

In this illustration, the angle bracket forms 14 a horizontal connection level to the holding lance 15 in which the following lying in the following lines are connected via corresponding connections: a gas line 45 with a gas connection 46 over which a plasma nozzle 11 with the gas for the hot gas jet 12 is loadable; a coolant line 47 with a coolant connection 48 , via which, for example, an accompanying cooling is ensured with compressed air; a supply line 43 with a feed connection 44 , via which, preferably by means of a transport gas, coating material, for example a metallic powder, can be supplied.

The plasma nozzle 11 The type shown here has a cathode 40 including, for example Tungsten, and a nozzle body as an anode 41 between which an electrical voltage can be applied, so that an arc is generated. The gas flowing through the anode is thereby heated and at least partially ionized, and thus the hot gas jet 12 generated. About the volume flow via the gas line 45 and the shape of the nozzle body, so the anode 41 , will adjust the speed, temperature and center axis alignment 17 the hot gas jet 12 established. The hot gas jet 12 here is powder by means of a feeder 13 , which via the supply line 43 can be supplied, laterally transversely fed. The particles of the cone beam thus generated 19 be by means of the hot gas jet 12 in the beam direction 33 entrained and against the surface to be coated 10 spun and remain permanently adhered to produce a desired surface property such as low roughness and good flatness as a tread for a piston of an internal combustion engine. In the purely schematic representation hereof, the resulting coating effective cone beam 19 with a flattened surface line 20 and an inclined surface line 39 with its (not shown) cone height to the center axis alignment 17 offset laterally and inclined downwards. This is a consequence of the feed rate of the coating material and the parameters of the hot gas jet 12 , The inclined generatrix 20 closes with the insertion direction 16 a maximum angle 21 one. In the present example, the maximum angle is 21 about 80 °.

In 2 is a masking shield 300 with an asymmetrically arranged passage opening 26 with an axial extent 27 for a coating lance 200 shown. The masking shield 300 is with its underside hidden here 23 on an object only partially shown 22 lowered, so that here a hidden predetermined surface 24 is shielded, but the coating lance 200 in the interior 38 is submersible. The object 22 For example, is a cylinder crankcase of an internal combustion engine and the interior 38 a cylinder bore. The passage opening 26 This is a little larger than the diameter of the interior to be coated, so when immersing and dipping the operated coating lance 200 an edge coating can be generated. The top 25 is, for example concentric to the axial extent 27 , inclined and closes in this example directly to the passage opening 26 at. The upper side is in the radially outer gap-free, for example in one piece, in an outdoor area 29 above. The outdoor area 29 is here parallel to the bottom 23 and thus from the top 25 away to the object 22 inclined.

In 3 is a masking shield 300 or a substantially on the top 25 limited section of a masking shield 300 shown in plan view. Central to the top 25 is one to the axial extent 27 concentric passage opening 26 shown. The top 25 goes into a weggeneigten outdoor area 29 over, which is formed here only by a chamfer. By a dashed line with also dashed reference line is a rear-side remote area 30 indicated. The remote area 30 is formed in this example as a strip, which in the figure from left to right over the entire width of the masking shield 300 extends and also bulges in the vicinity of the passage opening 26 forms, so that one to the axial extent 27 predetermined minimum distance is formed. In this figure also a sectional plane AA is marked, which in the figure perpendicular through the axial extent 27 is guided.

In 4 is a section of a section along the cutting plane AA of the masking shield 300 , as in 3 shown, shown. Here is an opening angle 28 which from the top 25 and the axial extent 27 is enclosed, provided by about 80 °. Here, a particularly preferred variant is shown in which the top 25 initially at an angle of about 5 ° acute from the edge of the through hole 26 radially outward at an angle of about 15 ° passes before the top 25 in the outdoor area 29 , for example, a chamfer passes. Furthermore, here is the remote area 30 at which the bottom 23 is formed, shown. In this embodiment, the planar underside border 23 and the top 25 at the edge of the passage opening 26 directly to each other.

In 5 is a similar cut as in 4 shown here, wherein here another embodiment of the masking shield 300 is shown. For the same elements with the same reference numerals, reference is made to the preceding description. Here is the top 25 plan and with an opening angle 28 formed by about 82 °. In this embodiment, the top is adjacent 25 not directly to the bottom 23 but in between is a chamfer 49 educated. This chamfer 49 points to the plan bottom 23 a Anliegewinkel 50 from about 45 °.

In 6 is a purely schematic sectional view of a coating system 600 for a cylinder crankcase 35 shown. This includes a coating system 400 comprising a masking shield 300 and a coating lance 200 which is in a process box 500 is arranged. The cylinder crankcase 35 Here is the object to be coated 22 , being a first interior 38 one to the axis of rotation 42 rotationally symmetrical cylinder bore, on the surface to be coated 10 already with one coating 52 , which is shown here by dashed lines, has been provided. All other surfaces 24 of the object to be coated 22 were in the previous coating process using the masking shield 300 or the process box 500 shielded.

The cylinder crankcase 35 is by means of an automated or manually fed delivery system 36 , For example, a turntable, by means of a rotation in the direction of rotation 54 around the axis of rotation 53 for coating by means of the coating lance 200 been delivered. The process box 500 is along the Aufsetzbewegungsrichtung 55 with the bottom 23 of the masking shield 300 on the surface to be screened 24 been set up. Subsequently, the already a stable cone beam 19 generating coating lance 200 through the passage opening 26 through into the interior 38 has been immersed and has there at least once by immersing and dehumidifying the coating 52 on the surface to be coated 10 generated. After completion of the coating 52 is the coating lance 200 again through the passage opening 26 has been dipped and the process box 500 along the Aufsetzbewegungsrichtung 55 been raised.

In the illustrated state, the coating lance is 200 in a fully immersed position, in which the entire coating effective cone beam 19 inside the case 32 the process box 500 is directed. Due to the inclination of the cone beam 19 by means of the center axis alignment 18 (see. 1 ) is the maximum angle 21 approximately parallel to the opening angle 28 the top 25 aligned. The discharge angle 31 between the inclined generatrix 20 and the top 25 is here about 0 °. Up to a radiant end 34 According to which, in the illustration to the left, there are no more coating-active particles, the cone beam hits 19 not on a counter surface. In addition, the top borders 25 here at a weggeneigten outdoor area 29 so that only a vertical wall of the housing 32 the process box 500 could form a counter surface. That a coating-effective particle up to there over the radiant end 34 is accelerated and remains stuck is very unlikely. So that now is ensured that the dust generated by the through hole 26 in the area of the object to be coated 22 passes, is still a suction system 37 provided, which resulting dust by means of the suction openings 51 far outside of the coating effective cone beam 19 arranged sucks. Lines and filters are outlined here.

With the flat discharge angle generated in this way, the service life, which is limited in the state of the art due to adhesion, is considerably increased compared to a conventional coating installation.

LIST OF REFERENCE NUMBERS

100

Coating lance head

200

coating lance

10

metallic surface

11

plasma nozzle

12

Hot gas jet

13

feeding

14

bracket

15

retaining lance

16

insertion

17

Central axis alignment

18

beam angle

19

cone beam

20

weggeneigte generatrix

21

maximum angle

300

masking plate

22

object

23

bottom

24

surface to be shielded

25

top

26

Through opening

27

axial extent

28

opening angle

29

outdoors

30

remote area

400

coating system

31

Abführwinkel

500

ProcessBox

32

casing

33

beam direction

34

radiant

600

coating plant

35

cylinder crankcase

36

Zustellanlage

37

extraction

38

inner space

39

inclined generatrix

40

cathode

41

anode

42

axis of rotation

43

feed

44

supply port

45

gas pipe

46

gas connection

47

Coolant line

48

Coolant connection

49

chamfer

50

Anliegewinkel

51

suction

52

coating

53

axis of rotation

54

direction of rotation

55

Aufsetzbewegungsrichtung

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The 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

• WO 2016/015922 A1 [0004, 0006]
• EP 1141438 B1 [0007]
• WO 2014/015922 A1 [0054]

Claims (10)

A coating lance head (100) for thermal coating a metallic surface (10), comprising at least the following elements: - Plasma nozzle (11) for generating a hot gas jet (12), the hot gas jet (12) having a predeterminable temperature, velocity and centerline orientation (17) ; - Feeding means (13) for supplying coating material in solid phase to the hot gas jet (12); and - angle holder (14) for fixing the coating lance head (100) to a holding lance (15), wherein the holding lance (15) has an insertion direction (16), characterized in that by means of the angle holder (14) in the holding lance (15) connected state between the insertion direction (16) of the holding lance (15) and the center axis alignment (17) of the hot gas jet (12) to the holding lance (15) inclined inclining beam angle (18) is formed, which is smaller than 90 °. Coating lance head (100) according to Claim 1 , wherein in the coating operation the supplied coating material as a result of the acceleration by means of the hot gas jet (12) forms a coating effective cone beam (19) and between the maximum of the insertion direction (16) of the holding lance (15) inclined away generatrix (20) of the cone beam (19) and the Insertion (16) of the holding lance (15) an enclosed maximum angle (21) is formed, which is equal to or less than 90 °. A coating lance (200) for thermally coating a metallic surface (10), comprising at least the following elements: - Plasma nozzle (11) for generating a hot gas jet (12), the hot gas jet (12) having a predeterminable temperature, velocity and centerline orientation (17) ; - Feeding means (13) for supplying coating material in solid phase to the hot gas jet (12); and holding lance (15), wherein the holding lance (15) has an insertion direction (16), characterized in that between the insertion direction (16) of the holding lance (15) and the center axis alignment (17) of the hot gas jet (12) to the holding lance (15) is included included beam angle (18) which is smaller than 90 °. A masking shield (300) for shielding predetermined surfaces (24) of an object (22) in a thermal coating, comprising at least the following elements: - underside (23) for bearing on a surface (24) to be screened; - top (25) which faces a coating lance (200) when the coating lance (200) is in an extended position; - Through opening (26) having an axial extent (27) from the top (25) to the bottom (23) through which a coating lance (200) is submersible to coat the object (22), characterized in that the top (25) to the axial extent (27) of the passage opening (26) forms an enclosed opening angle (28), which is greater than 75 °. and the upper side (25) has an anti-adhesion property at least in the region of the passage opening (26). Masking shield (300) after Claim 4 , wherein the upper side (25) extends with the opening angle (28) up to the passage opening (26). Masking shield (300) after Claim 4 or 5 wherein the underside (23) has a stepped portion (30) which has low roughness and high flatness, preferably polished. Coating system (400) for thermally coating a metallic interior surface (10), comprising a coating lance (200), preferably after Claim 3 , and a masking shield (300), preferably according to one of Claims 4 to 6 , characterized in that in the coating operation of the coating lance (200) of above the top (25) ejected portion of the cone beam (19) in a flat discharge angle (31) is aligned to the top (25), wherein the discharge angle (31) between the Proportion of the cone beam (19) and the top (25) is less than 10 ° or negative, preferably between 5 ° and -45 °. A process box (500) for thermally coating a metallic interior surface (10), comprising at least one coating system (400) Claim 7 wherein the at least one coating system (400) is integrated into a closed, suctionable housing (32), wherein the coating-effective cone beam (19) has a beam end (34) in the beam direction (33), after which the cone beam (19) is no longer coating-effective and wherein the coating-effective cone beam (19) can strike the radiating end (34) only on the top side (25) of the masking shield (300) or on an unsuitable surface (10). Coating plant (600) for thermal coating of a cylinder crankcase (35) for an internal combustion engine, comprising at least the following elements: - delivery system (36) for aligned delivery of at least one cylinder crankcase (35), preferably a turntable; - Process box (500) to Claim 8 which as a unit on at least one delivered cylinder crankcase (35) with the underside (23) of the masking shield (300) is sealingly lowered; and - exhaust system (37) for exhausting coating material discharged into the process box (500). Process for the thermal coating of a metallic interior surface (10) of an object (22), preferably by means of a coating lance (200) Claim 3 comprising at least the following steps: a. Operating a stable coating effective cone jet (19) by means of a hot gas jet (12) and a coating material in a deployed position so that an interior surface (10) to be coated is not hit by the cone jet (19), at least not coating effective; b. at the same time as or before step a., aligned placement of a masking shield (300), preferably according to one of Claims 4 to 6 , on a surface (24) of the object (22) to be shielded, with a through-opening (26) aligned such that surfaces (24) of the object (22) to be shielded by means of the masking shield (300) in each axial operating position of the cone beam (19) a coating are protected and by means of the passage opening (26) to be coated interior surface (10) for the cone beam (19) is accessible for coating; c. then after step a. and b., along an insertion direction (16) immersing the coating effective cone beam (19) in the interior (38) with the interior surface to be coated (10), wherein the coating effective cone beam (19) one of the insertion direction (16) maximum inclined away Mantellinie (20), and wherein the passage-opening-side angle of incidence between the maximally inclined surface line (20) and the interior surface to be coated (10) is equal to or greater than 90 °, preferably greater than 95 °.

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