Perforated plate for an application device and corresponding method

Abstract

A perforated plate is provided for an application device for the application of a coating agent, in particular a paint, a sealant, a glue or a separating agent, to a component, in particular to a motor vehicle body component. The perforated plate contains at least one through-hole for passing the coating agent through and a hole exit opening on the side of the perforated plate that is located downstream with a wetting surface that can be wetted during operation by the coating agent. The through-hole, to reduce the wetting tendency, transitions into a protruding pipe stub or has a structure that reduces the wetting tendency and/or improves the flushability, e.g., a microstructuring or a nanostructuring.

Claims

1. An apparatus for an application device, the device configured to apply a coating agent to a component, the coating agent being one of a paint, sealant, and glue, the apparatus comprising: a perforated plate; a pipe stub protruding from a downstream side of the perforated plate; a through-hole extending from an upstream side of the perforated plate and a free end of the pipe stub opposite the perforated plate, the through-hole configured to pass the coating agent through, the through hole having an internal diameter of less than 200 micrometers; an inlet opening for the through-hole on the upstream side of the perforated plate; an exit opening for the through-hole on the downstream side of the perforated plate, wherein the pipe stub has an outer circumferential surface which tapers toward the free end, the free end configured to define therewithin a wetting surface for the coating agent passing through the through-hole, the pipe stub having a length of less than 500 micrometers, and a free end that is less than 100 micrometers wherein a wetting tendency is reduced; and, the perforated plate having a thickness of less than 1 millimeter in the region of the through-hole.

2. The apparatus of claim 1, wherein the through-hole forms a Laval nozzle.

3. The apparatus of claim 1, wherein the pipe stub has at the free end a mouth opening that is inclined relative to the longitudinal axis of the pipe stub.

4. The apparatus of claim 1, comprising at least one of the following features: the pipe stub has a wall thickness which is smaller than an internal diameter of the through-hole; the through-hole has an internal cross-section which is substantially constant along its longitudinal axis; the pipe stub has a lateral wall thickness of at most 100 micrometers; the pipe stub between the downstream side of the perforated plate and the free end of the pipe stub has a length in the range from 25%-100% of a thickness of the perforated plate; the pipe stub between the downstream side of the perforated plate and the free end of the pipe stub has a length that is greater than 10 micrometers and less than 1 millimeter.

5. A perforated plate for an application device for the application of a coating agent to a component, comprising: at least ten through-holes extending between an upstream side of the perforated plate and a downstream side of the perforated plate, each configured to pass the coating agent therethrough, each of the through holes having an internal diameter of less than 200 micrometers; and protrusions from at least one of the upstream side of the perforated plate and the downstream side of the perforated plate at each of the at least ten through-holes, the protrusions having a length of less than 500 micrometers and a free end that is less than 100 micrometers wherein a wetting tendency is reduced, wherein a surface density of the at least ten through-holes, distances between the at least ten through-holes, and internal cross-sectional shapes of the at least ten through-holes are dimensioned such that the coating-agent jets emerging from the through-holes, after impinging on the component, form a coherent coating-agent film.

6. The perforated plate of claim 5, wherein the internal cross-sectional shapes of the at least ten through-holes are substantially equal.

7. The perforated plate of claim 6, wherein each of the at least ten through-holes are substantially equally spaced apart from adjacent ones of the other of the at least ten through-holes.

8. The perforated plate of claim 7, wherein the at least ten through-holes are substantially equally spaced apart at a distance that is at least three times a diameter of the internal cross-sectional shapes of the at least ten through-holes.

9. The perforated plate of claim 5, wherein one or more of the internal cross-sectional shapes of the at least ten through-holes is different than one or more of the internal cross-sectional shapes of the other of the at least ten through-holes.

10. The perforated plate of claim 5, further comprising a semiconductor material.

11. The perforated plate of claim 5, wherein the protrusions are positioned on the downstream side of the perforated plate and extend less than 1 millimeter from the perforated plate.

12. The perforated plate of claim 5, wherein the at least ten through-holes are each arranged at a corner of a polyhedron shape.

13. The perforated plate of claim 5, wherein the at least ten through-holes are arranged with longitudinal axes respectively parallel relative to each other, each of the longitudinal axes having an angular deviation of less than one degree relative to a direction normal of the perforated plate.

14. The perforated plate of claim 5, further comprising a coating of the perforated plate on at least one side of the perforated plate, the coating being at least one of a constituent of a sensor and a constituent of a logic circuit.

15. The perforated plate of claim 14, further comprising at least one reinforcing strip, the perforated plate having a lesser thickness at the reinforcing strip than at the at least ten through-holes.

16. The application device of claim 5, wherein the perforated plate is a constituent of one of the following components: a) nozzle, b) nozzle insert, c) shaping air ring, d) diaphragm, e) mixer, f) screen, g) valve needle, h) needle seat.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other advantageous developments are characterised in the claims, or will be explained in greater detail below with reference to the figures together with the description of examples of embodiments. These show:

(2) FIG. 1 shows a top view of an example perforated plate;

(3) FIG. 2 shows a cross-sectional view through a through-hole in the perforated plate of FIG. 1;

(4) FIG. 3 shows a modification of FIG. 2;

(5) FIG. 4A shows a cross-sectional view through a through-hole in the perforated plate in another variant;

(6) FIG. 4B shows the cross-sectional view of FIG. 4A with coating agent in the through-hole;

(7) FIG. 5A shows a modification of FIG. 4A with an additional pipe stub in order to reduce the wetting surface;

(8) FIG. 5B shows the cross-sectional view of FIG. 5A with coating agent in the through-hole;

(9) FIG. 6A shows a modification of FIG. 5A with a conically tapering pipe stub;

(10) FIG. 6B shows a modification of FIG. 6A with an inclined mouth opening of the pipe stub,

(11) FIG. 6C shows a modification of FIG. 5A with an inclined mouth opening of the pipe stub;

(12) FIG. 7A shows a diagrammatic cross-sectional view through an example perforated plate with a reinforced edge and a thinner central region with the through-holes,

(13) FIG. 7B shows a modification of FIG. 7A;

(14) FIG. 8A shows a diagrammatic cross-sectional view through an example perforated plate with reinforcing strip;

(15) FIG. 8B shows a top view of the perforated plate of FIG. 8A;

(16) FIG. 9 shows an example insert with a plurality of perforated plates,

(17) FIG. 10 shows an example application device with an example perforated plate, and

(18) FIG. 11 shows a modification of FIG. 2.

(19) FIG. 1 shows a top view of an example perforated plate 1 that can be used, for example, in a droplet generator. With regard to the design details of the droplet generator, reference is additionally made also to DE 10 2010 019 612 A1, so the contents of this patent application should be included in the present description, and are hereby incorporated by reference herein, in their entirety.

(20) The perforated plate 1 has a large number of through-holes 2 which are arranged in the perforated plate 1, the through-holes 2 being arranged in the perforated plate 1 equidistantly and in a matrix.

(21) The perforated plate 1 is distinguished in this case by etching production.

(22) FIG. 2 shows a cross-sectional view through the perforated plate 1 in the region of one of the through-holes 2, the arrow in the cross-sectional view indicating the direction of flow of the coating agent through the through-hole 2. It can be seen from the cross-sectional view that the through-hole 2 has a hole inlet opening 3 which is optimised in terms of flow, which reduces the flow resistance of the through-hole 2.

(23) Furthermore, the perforated plate 1, on the side that is located downstream, on the peripheral edge of the through-holes 2 has in each case a structuring which reduces the wetting tendency.

(24) In the example of FIG. 3, the through-hole 2, in addition to the hole inlet opening 3 which is optimised in terms of flow, also has a hole exit opening 4 which is optimised in terms of flow, so that the through-hole 2 forms a Laval nozzle.

(25) FIGS. 4A and 4B show an alternative cross-sectional view through the perforated plate 1 in the region of a through-hole 2, FIG. 4A showing the through-hole 2 without a coating agent, whereas a coating agent 5 is illustrated in FIG. 4B.

(26) It can be seen from this that the coating agent 5 wets a wetting surface 6 on the surface of the perforated plate 1 that is located downstream, which makes detachment of the coating agent 5 from the perforated plate 1 in jet form difficult despite the structuring.

(27) FIGS. 5A and 5B show an embodiment with a wetting tendency which is reduced further. For this, the perforated plate 1 has in each case on the peripheral edge of the individual through-holes 2 a pipe stub 7, the through-hole 2 transitioning into the pipe stub 7, so that the end face of the pipe stub 7 forms a wetting surface 8 at the free end of the pipe stub 7. The wetting surface 8 is therefore restricted to the free end face of the pipe stub 7 and hence is considerably smaller than the wetting surface 6 according to FIG. 4A. This facilitates the removal of the coating agent 5 from the perforated plate 1.

(28) The pipe stub 7 in this case protrudes from the surface of the perforated plate 1 that is located downstream with a length L=100 m.

(29) FIG. 6A shows a modification of FIG. 5A, with the outer circumferential surface of the pipe stub 7 tapering conically to the free end of the pipe stub 7, so that the wetting surface at the free end of the pipe stub 7 is minimal.

(30) FIG. 6B shows a modification of FIG. 6A, with the mouth opening of the pipe stub 7 being inclined relative to the longitudinal axis of the through-hole 2.

(31) FIG. 6C shows a modification of FIG. 5A, with the mouth opening of the pipe stub 7 being inclined relative to the longitudinal axis of the through-hole.

(32) FIG. 7A shows a diagrammatic cross-sectional view through an example perforated plate 1, which partially matches with the perforated plates described above, so reference is made to the above description in order to avoid repetition, with the same reference numerals being used for corresponding details.

(33) One special feature of this example is that the perforated plate 1 has on the outside a relatively thick edge 9 and in the middle a thinner region 10 with the through-holes 2. The thick edge 9 of the perforated plate 1 in this case ensures sufficient mechanical stability, while the reduction in thickness in the region 10 with the through-holes 2 ensures that the through-holes 2 offer only relatively low flow resistance.

(34) FIG. 7B shows a modification of FIG. 7A, so reference is made to the description for FIG. 7A in order to avoid repetition, with the same reference numerals being used for corresponding details.

(35) One special feature of this example is that the region 10 in this case is reduced in its thickness only on one side.

(36) FIGS. 8A and 8B show a perforated plate 1, which partially match with the examples described above, so reference is made to the above description in order to avoid repetition, with the same reference numerals being used for corresponding details.

(37) One special feature of this example is that thicker reinforcing strips 11 are also provided in addition to the edge 9 of the perforated plate 1.

(38) The sharp edges and corners shown in the figures are illustrated only by way of example, and may advantageously also be designed to be rounded-off, in order to configure them more optimally in terms of flow or in order to achieve better flushability.

(39) FIG. 9 shows a holding mechanism 12 with three perforated plates 13, 14, 15 which directly adjoin one another.

(40) Further, FIG. 10 shows, in a greatly simplified diagrammatic representation, an application device with an example perforated plate 1 for coating a component 16 (e.g. a motor vehicle body component).

(41) In this case, coating-agent jets 17 emerge out of the individual through-holes 2 in the perforated plate 1, as is known per se from DE 10 2010 019 612 A1. After impinging on the surface of the component 16, these coating-agent jets 17 form a coherent coating-agent film on the surface of the component 16.

(42) Furthermore, the drawing also shows an applicator 18 connected to the perforated plate 1, and also application technology 19 which is connected to the applicator 18 by diagrammatically illustrated lines.

(43) Finally, FIG. 11 shows a modification of FIG. 2, so in order to avoid repetition reference is made to the above description relating to FIG. 2, with the same reference numerals being used for corresponding details.

(44) One special feature of this example of embodiment of the through-hole 2 is that the through-hole 2 initially has a cylindrical region 20 with an internal diameter d1 on the hole inlet opening that is located upstream.

(45) The cylindrical region 20 is then adjoined in the direction of flow by a conical region 21 which tapers in the direction of flow and has an internal diameter d2 at the hole exit opening.

(46) What is important here is that the internal diameter d2 of the hole exit opening is substantially smaller than the internal diameter d1 of the cylindrical region 20.

(47) The invention is not limited to the preferred examples of embodiment described above. Rather, a large number of variants and modifications which likewise make use of the inventive concept and therefore come within the scope of protection are possible. In particular, the invention also claims protection for the subject-matter and the features of the dependent claims independently of the claims referred to. Thus the description also contains design details which are suitable for perforated plates which are not produced by etching.