JP2001046927A - Electrostatic rotary atomizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a spray pattern of an extremely small diameter in a large amt. of lacquer per unit time with the spray quality matching a large-diameter rotary atomizer. SOLUTION: This atomizer is an electrostatic rotary atomizer for applying a coating agent, especially paint, lacquer, etc., and has an atomization head 2 arranged on a shaft 4 to be rotated and a coating agent nozzle 8 in the inside 9 of the head 2, In this case, the head has plural jet holes 13 each provided with a coating agent atomizing edge 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a statically actuated coating which is operated by the electrostatic charge of a coating material to be applied and which has a spraying head which is arranged on a rotary drive shaft and comprises a coating material nozzle. The present invention relates to an electric rotary spray device.

[0002]

2. Description of the Related Art A coating material such as paint or lacquer is generally supplied to a stationary nozzle inside a driven hollow shaft. From the nozzle, the coating material reaches a rapidly rotating, generally bell-shaped spray head, which is finally discharged from its spray edge.
These features are the German utility model (deutscher Gebrauchsm
uster) No. 9217458. The sprayed lacquer must move axially forward so that the lacquer particles ejected radially from the spray edge reach the substrate. For this reason, in addition to the electrostatic force acting in this direction, the induced airflow (Lenkluft
stroemung) is also used. The induced air flow is emitted from the rim of the hole (Kranz) behind the rotary bell atomizer and then acts axially on the atomized lacquer particles.

[0003] Depending on the diameter of the bell type spray device and the number of revolutions, the spray pattern has a diameter of about 500-700 mm.
It is. In such a coating process, the radial centrifugal force and
The radial air flow caused by the rotary atomizer also overlaps the induced air flow acting in the axial direction.

[0004] Especially when spraying metallic lacquer,
Said boundary conditions lead to the achievement of a metallic effect with a configuration which is significantly different from that of applying metallic lacquer with a conventional air atomizing spray gun.

[0005] As a result of the metallic effect of this different construction, the second layer of metallic lacquer is actually applied in most cases not with an electrostatic spray device but with a conventional air-spray-type spray gun, so that the lacquer loss Significantly increase.

[0006] Furthermore, it is difficult to achieve a spray pattern diameter of less than 400 mm when the lacquer is automatically electrostatically sprayed with a bell type sprayer. This problem occurs, for example, when painting thin profile strips, or when the lacquer has to reach undercuts, depressions or other so-called Faradaysche Kaefig.

When the diameter of the bell-shaped spraying device is selected to be significantly smaller than usual, it is basically possible to achieve a spray pattern even with a smaller diameter.
However, with this, the length of the spray edge is reduced and the spray capacity is reduced, so that such bell-type rotary spray devices can only process significantly less lacquer per unit time.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to generate a spray pattern having a diameter as small as possible with a spray quality comparable to that of a large-diameter rotary spray apparatus at a high lacquer amount per unit time. It is an object of the present invention to provide a rotary spraying device having a spraying head.

[0009]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention provides a spray head having a plurality of spraying edges for a coating material on a peripheral surface thereof, the spraying heads being arranged at a distance from each other in an axial direction. It has a vent.

As a result of the present invention, a spray head suitable for producing small spray patterns can still spray the same amount of lacquer as previously known large diameter spray heads, despite the small diameter. . It is important that the orifices with a sufficient number of spray edges are provided in the spray head, wherein the orifices are preferably arranged in a plurality of spray edges arranged one behind the other in the axial direction. To form The spray pattern achievable with such a spray head has the desired small diameter and is capable of processing large quantities of lacquer per unit time. Finally, the metallic effect during the metallic lacquer treatment has the same phenomenon pattern as when using the air spray type spray gun. The penetration of the sprayed charged lacquer into the shape having the action of the Faraday box can also be realized better.

[0011] Other features of the invention will become apparent from the dependent claims, taken in conjunction with the specification and drawings.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail below with reference to an embodiment shown in the drawings.

1 comprises a spray head 2 which is mounted in a housing 3 on a shaft 4 in a basically known manner. This shaft 4 is a hollow shaft. A supply pipe 5 inside the shaft is provided with lacquer or cleaning agent holes 6, 7. The holes 6, 7 lead to a nozzle 8 at the free end of the supply pipe 5. According to FIG. 2, there is a nozzle 8 which is also stopped during the painting process, inside the spray head 2.

The driving of the hollow shaft 4 and the opening 6 in the supply pipe 5
The installation of 7 is not different from the known rotary spray device. The nozzle 8 also serves to guide and discharge the liquid coating or cleaning agent in a manner known per se. However,
The nozzle 8 or its hole is desirably formed such that a fan-shaped jet or a conical jet is generated instead of a cylindrical jet.

The spray head 2 comprises, according to an embodiment, a holding and supporting element 10 which is substantially cylindrical on the outside, which serves at the same time to be fixed to the free end 11 of the shaft. The nozzle 8 is in this case approximately at the center of the spray head 2.

According to a first embodiment, a multi-part spray element 12 is arranged axially in front of the nozzle 8 or to the left in FIG.

The spray head 2 has in the area of the spray element 12 a plurality of coating or cleaning orifices 13 which are arranged at a distance from one another on the circumferential side (umfangsseitig) and in the axial direction. The jet holes 13 extend over the entire peripheral surface of the spray element 12 or the spray head 2, respectively. According to the embodiment, nine annular ejection holes 13 are provided in the spray head 2.

Two circular spray edges 14 extending in the circumferential direction
Belong to each ejection hole 13. For the nine orifices 13, the spray head 2 has twice the number of spray edges 14, each axially spaced from one another.

At least one supply surface 15 for the liquid to be treated and / or at least one supply passage 16 are provided for each two spray edges 14.

A plurality of disks 17 help form the spray edge 14. According to the embodiment, the disk 17 is annular. According to the embodiment, the outer diameters of all the disks 17 are equal. The hole 18 located at the center of the disk 17 is graded for each disk, and the disk 19 adjacent to the nozzle 8 has the largest diameter hole and the termination disk 20 (Ab
The disk 21 at or closest to it has the smallest hole diameter.

According to the preferred embodiment, the termination disk 20 has a centrally located orifice 20 '. The outlet 20 'has a shape similar to that of a Laval-Duese. A part of the liquid supplied from the nozzle 8 to the spray element 12 is ejected from the central ejection hole 20 ′, and the exposed front surface 20 ″ is centrifuged.
Through the spray edge 14 '.

All of the disks 17 and, according to the embodiment, also the terminating disk 20 have an annular ridge or bund 22 on the side facing the nozzle 8. The outer diameter of each annular flange 22 is smaller than the outer diameter of the disk 17. The inner diameter of the flange 22 is larger than the diameter of the hole 18 of the disk 17. As a result, the slit-shaped groove 23 is located on the peripheral surface of the spray element 12 in the assembled state, and the ejection hole 13 having the spray edge 14 is formed.

A number of radially oriented feed passages 16 communicate with each spray edge 14. The supply passages each have a triangular cross-section in the region of each collar 22, which is particularly evident from the illustration of FIG. Each collar 22
In the region of the annular supply surface 15 which is radially outward, the supply passage 16 which has a triangular cross section in the region of FIG. Therefore, the outer annular supply surface 15 is knurled according to the embodiment shown in FIGS.

The notch 16 'attached to the supply passage 16 is gradually terminated radially inward of the disk 17 or 20 at the nozzle-side front and before reaching the hole 18.

The fixing means 25, for example, in the form of a screw, serves for fixing the disc 17 including the terminating disc 20 arranged on the front side. The mounting means is passed through the hole 26.
These holes 26 are preferably each in the region of the collar 22 of the disc 17.

The disks 17 can be secured together or secured to the holding and supporting element 10 by other bonding techniques such as gluing, clamping and the like.

The disk 1 is attached by the mounting means 25 or screws.
7 and 20 are fixed to the holding and supporting element 10. The holding and supporting element 10 is cylindrical or annular. According to FIG. 2, the holding and supporting element is cylindrical on the outside and stepped on the inside and can be fixed to the free end 11 of the shaft 4.

An annular disk 1 serving as a spray disk
7 causes the liquid flowing from the nozzle 8 to be distributed in the gap between the disks 17 based on various hole diameters. The liquid is then fed there radially to the spray edge 14. The large number of spray edges 14, or their total length, provided in correspondence with the number of disks 17, makes it possible to process large quantities of lacquer per unit time with high quality, even if the diameter of the disks 17 is small.

FIG. 3 shows a section along the line III--III of FIG. 2, but with the spray head 2a in a modified form. Basically, the same parts have the same reference numerals and the suffix a.

The spray head 2a differs from the spray head 2 only in that the annular supply surface 15a radially outward between the flange 22a of each disk 17a and the spray edge 14a is not knurled. . The disk has a smooth annular surface.

The details shown in FIG.
7b, this disc has, instead of a smooth supply surface 15a, a supply surface 15b provided with spots near the spray edge 14b.

Other modifications of the disk 17 shown in FIGS. 2 and 6 will be apparent from FIGS. 7 and 8. Disk 17
c is an annular blade (Ringsc) that restricts the hole 18c on the nozzle side.
hneide) 27c. The annular blade 27c guides the impinging liquid flow radially outward to the adjacent annular surface 28c. All disks have a comparable annular surface 28c (FIG. 3).

As will become more apparent from FIG. 7, the disk 17c may have an outer edge 31c that is bent relative to the disk plane 30c and carries the spray edge 14c. The truncated conical outer edge 31c diverts the liquid flowing radially outward, thereby reducing the radial acceleration of the liquid and accelerating tangentially. Supply surface 15c
Can be smooth or knurled according to FIG.

FIG. 8 shows details of another disk 17d that is fully or partially curved. Its supply surface 15d can also be smooth or can be knurled according to FIG. 8, and can therefore have a groove 32d like other knurling disks.

The nozzle 8 at the free end of the supply pipe 5 produces a conical or fan-shaped liquid flow. This is shown in FIG.

Another spray head 2e with an alternative spray element 12e is shown in FIG. Holding and supporting element 1
0e almost coincides with that of the embodiment of FIG. A porous body 33e is used to form a jet hole 13e with a spray edge 14e associated with each. The porous body 33e is annularly disposed on the holding / supporting element 10e on the front side. As in the case of the spray head 2 of FIG. 2, the termination disc 20e closes the spray element 12e on the front side.

The liquid scattered from the nozzle 8e to the inner contour (Innenkontur) 34e of the spray element 12e is applied to the spray element 12e.
e, through the porous structure to the orifice 13e, and then discharged from its spray edge 14e.

Another embodiment of FIG. 11 has a buechsenfoermigenKoerper 35f as the spray element 12f. A radially extending through hole 37f is present in the bush-like cylindrical wall 36f. The radially outer end of the through hole forms an orifice 13f and an associated spray edge 14f.

The bush 35i is also sprayed with the spray element 12i.
FIG. 12 shows a last embodiment of the spray head 2i provided as a nozzle. The cylindrical wall 36i has a number of slots 38i to form the outlet 13i and the associated spray edge 14i. The slot extends from the inner contour 34i having a constant cross section to the spray edge 14i. The slots 38i are arranged in a plurality of linearly arranged rows in the circumferential direction, and their longitudinal axes are parallel to the center line 24i of the spray head 2i.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a rotary spray device.

2 is a cutaway enlarged sectional view of the spray head having the knurled spray edge of FIG. 5;

FIG. 3 I of FIG. 2 having a smooth annular surface in addition to the spray edge
FIG. 3 is a sectional view taken along line II-III.

FIG. 4 is a detailed view of a spray edge having a sequence of speckles.

FIG. 5 shows details of the knurled spray edge in FIG.
FIG.

FIG. 6 is a cross-sectional view of a spray disk having a knurled spray edge.

FIG. 7 is a cutaway sectional view of a spray disk according to a modified embodiment.

FIG. 8 is a cutaway sectional view of a spray disk according to another modification.

FIG. 9 is a sectional view showing a holding and supporting element of the spray head in the same manner as in FIG. 2;

FIG. 10 is a sectional view showing a spray head according to a modified embodiment, similarly to FIG. 2;

FIG. 11 is a sectional view showing another spray head in the same manner as in FIG. 2;

FIG. 12 is a sectional view of the last embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotary spray device 2 spray head 4 rotary drive shaft 8 coating agent nozzle 9 spray head interior 12 spray element 13, 13e, 13f, 13i ejection hole 14, 14c, 14e, 14f, 14i spray edge 15 coating agent supply surface 16 coating Agent supply passage 17, 17c, 17d Disk 18, 18c hole 20 Termination disk 20 'Spray hole 22 Annular flange 23 Slit groove 24i Center line 27c Annular cutting blade 28 Supply surface 33e Porous body 37f Through hole 38i Slot

Claims (20)

[Claims] 1. An electrostatic rotary spraying device for applying a coating material, in particular a paint, a lacquer or the like, comprising a spray head (2) arranged on a shaft (4) driven to rotate, and a spray head (2). ) With a coating nozzle (8) inside (9), a plurality of orifices (13) with a coating spray edge (14) are provided on the circumferential surface of the spray head (2) in the axial direction. A rotary spraying device, characterized in that they are arranged at a distance from one another. 2. An ejection hole (13e) and a spray edge (14).
2. The rotary atomizer according to claim 1, wherein a porous body (33e) is provided for forming e). 3. An orifice (13f) and a spray edge (14).
2. The rotary spraying device according to claim 1, characterized in that a radially oriented, circumferentially and axially juxtaposed through-hole (37f) is provided for forming f). 4. The rotary spray device according to claim 1, wherein slots (38i) are provided as jet holes (13i) and for forming spray edges (14i). 5. The slot (38i) has its center line (24i).
2. The device according to claim 1, wherein the first member extends in a direction parallel to the first member.
Or the rotary spray device according to 4. 6. A coating supply surface (15) and / or at least one coating supply passage (16) is provided for each spray edge (14).
The rotary spray device according to any one of claims 1 to 5. 7. The rotary spray device according to claim 1, wherein a slit-like groove (23) for forming a spray edge (14) is provided. 8. The rotary spraying device according to claim 1, wherein a plurality of disks (17) are provided for forming an annular spraying edge (14). 9. A disk (17) having a supply surface (15, 2).
9. The rotary atomizer according to claim 1, comprising a supply channel and a supply channel. 8. 10. The rotary atomizer according to claim 1, wherein the disk (17) is annular. 11. A disk (17c) having a spray edge (1).
11. The rotary spray device according to claim 1, wherein the rotary spray device is bent in a frustoconical shape in the region of 4c). 12. The disk according to claim 1, wherein the disk is at least partially curved.
The rotary spray device according to any one of claims 1 to 4. 13. The rotary spraying device according to claim 1, wherein the discs (17) have holes (18) of different diameters, respectively arranged in the center. 14. The disk as claimed in claim 1, wherein the diameter of the hole of the disk is reduced stepwise from the nozzle to the termination disk. The rotary spray device according to claim 1. 15. The rotary spray according to claim 1, wherein the disc (17, 20) has an annular collar (22) on one of its fronts or on both sides. apparatus. 16. The rotary spraying device according to claim 1, wherein the disk (17c) has on the nozzle side an annular blade (27c) for limiting the hole (18c). 17. The rotary spraying device according to claim 1, wherein the disk has a cutout on the front side. 18. The rotary atomizer according to claim 1, wherein the termination disk has an orifice arranged centrally. 19. The rotary spraying device according to claim 1, wherein the nozzle has a fan-shaped or conical liquid flow. 20. The rotary spraying device according to claim 1, wherein the spraying element comprises a variable number of spraying disks.