The invention will be explained in more detail in the following with reference to the drawing. There are shown in a schematic representation:
FIG. 1 a section through a cylinder block of an engine in a V design with a masking system in accordance with the invention;
FIG. 2 a masking body in detail;
FIG. 3 a masking system with a masking element and suction device.
FIG. 1 and FIG. 3 show, in an illustration in section, two simple embodiment variants of a masking system in accordance with the invention during the coating of a cylinder bore of an engine in a V design at which the function of a masking system in accordance with the invention is schematically explained which is designated in total in the following by the reference numeral 1.
In this connection, the masking system of FIG. 3 additionally includes a masking element 9 for the protection and for the better cooling of a cylinder running surface 4, 42 not to be coated.
In FIG. 1 and FIG. 3, a section through an engine block of an engine in the V design is shown whose two cylinder rows are arranged parallel to one another at an angle of inclination a in a known manner.
A first cylinder 6, 61, the right hand cylinder in accordance with the representation, is just being coated using a rotating plasma spray gun 1000 known per se. The plasma spray gun 1000 rotates around a longitudinal axis, as indicated by the arrow 1002, during the coating process in the cylinder 6, 61 and is guided during the coating process under rotation in the axial direction through the cylinder bore 5, 51. At a lower end of the plasma spray gun 1000, a plasma jet 1003 with coating material 1004 exits a spray opening 1001 and the cylinder running surface 4, 41 of the cylinder 6, 61 is coated with said coating material 1004.
In the example of FIG. 1, only just the upper half of the cylinder is provided with a thermal coating 2000. The plasma spray gun is still so far away from its lower reverse point that the plasma jet 1003 impacts the cylinder running surface 4, 41 in its full width.
In the example of FIG. 3, the plasma spray gun 1000 is already in the proximity of its lower reverse point, that is the plasma jet 1003 with coating material 1004 is not only incident on the cylinder running surface 4, 41 of the cylinder 6, 61 to be coated, but also already reaches a little into the crankcase of the V engine 3. Without the masking body 7 in accordance with the invention, the other cylinder running surfaces 4, 42 not to be coated as well as the inner surfaces of the crank chamber 2 would be contaminated by particles 1004 from the coating jet 1003 and would moreover be heated excessively by the plasma jet 1003.
The masking body 7 including the connector segment 71, the screen segment 72 and the fastening segment 73, is connected in FIG. 1 and FIG. 3 by means of a plurality of connection elements 8 to the crankcase 21 by screw connections not shown in any more detail.
Since the engine 3 of FIG. 3 is a highly sensitive high performance engine 3, a masking element 9 is additionally provided here in the cylinder bore 5, 52 of the second cylinder 6, 62 above all for the achieving of a better cooling and is configured in the present example of FIG. 3 as a hollow cylinder 9 and additionally includes a masking cover 91. The masking cover 91, which forms a cover on the second cylinder 6, 62 or on the marking element 9, includes a passage 911 with openings which is connected to the flow gap 12 configured between the masking cylinder 9 and the cylinder running surface 4, 42 which, in the example of FIG. 3, is made as an inlet passage 911 for the conveying of fluid 11 into the flow gap 12.
In this connection, the flow 10 of the fluid 11 in the flow gap 12 is generated by a suction means 13 which is shown only schematically in FIG. 3 and which generates a presettable underpressure in the crankcase in a manner known per se to the skilled person so that e.g. air 11 is sucked in through the openings of the passages 911 in the masking cover 91 which then flows through the flow gap 12 connected to the openings of the passages 911 so that the cylinder 6, 62 and thus also the complete engine block of the internal combustion engine 3 is additionally cooled and, on the other hand, a deposition of metal vapours on the cylinder running surface 4, 42 of the second cylinder 6, 62 can be prevented in an even more ideal manner.
In FIG. 2, a masking body 7 in accordance with the invention is shown in detail again for illustration.
The hollow masking body 7 includes a connector segment 71 for connection of the hollow body 7 to the cylinder bore 5, 51, 52 as well as a screen segment 72. Additionally, a fastening element 73 is provided between the connector segment 71 and the screen segment 72 and tapers in funnel shape from the connector segment 71 to the screen segment 72. Since the diameter of the fastening element 73 reduces in the direction towards the screen segment 72, the screen segment 72 can have a smaller diameter than the connector segment 71, whereby the coating particles to be led away can be led out of the crank chamber 2 in a more directed manner and at the same time, the tight space conditions in the crank chamber 2 can be taken into account better, which is often even more important.
The specific embodiment of FIG. 2 has a cover ring 74 which is releasably connected to the connector segment 71 so that, as described above, the whole masking body 7 does not have to be replaced between an activation treatment of the cylinder running surface 4, 41 and a subsequent coating process.
It is understood that the invention is not restricted to the described embodiments and in particular all suitable combinations of the embodiments shown are also covered by the invention.
Patent Application
20080017159
