DE1652390A1 - Device for the electrostatic coating of objects with liquid or powder coating material - Google Patents

Description

DR. IWG. ERNST MAIER

PAIElflASWAIT

8 MUNICH 23

WILLMATEESTH. 5 ■ TEMPO »2B SD SO, 29 Bl 03

, *. 40366 May 17, 1967

A 40466. EM / Mü / My

ERNST MUELLER company, air and paint spray technology., Winnenden, Bahnhofstrasse 28

Device 2 and electrostatic coating on objects with liquid or powdery coating material

(Addition to patent (patent application M 36 141 VIb / 75c))

Me j ^ rfindang Detrifft a device for elec tro st atisenen coating of objects with liquid or powder coating material, hereinafter simply called color, according to patent ..... (patent application M 56 141 v "Ib / 75c).

In the main patent there is a reference to the eleJrtrostatiecJaen Coating by means of a rotating,

Spartau $ dlft> mbar <r S --.- t ^ vj: fAj - '. I-' · · ■ ■ ■ ",. * 1än * o, i,! 4r.254i4 UvcMtam Η, ΑαίΚΒΜαι, ΜαΐίφΒη, Ητ.ίί & Ι Ρο «5 * οώ. MOndiQn U3S61

BATH

The spray head serving as a spammngelectrode is described with the additional use of “compressed air, in which the spray head revolving at a rate of 4000 to preferably 20 rpm and above was supplied. I'arbe from a throwing-off edge, which lies within a Faraday's cage, is thrown off and sprayed purely mechanically, and the sarb fog generated in a macnaniscnem way is only charged and in after reaching a certain distance from the throwing-off cane through the high-voltage field emanating from discharge edges or points In a known way, the force of the electric field as well as the compressed air to the ΰ-object is undirected and ζ \ λ is conveyed. To carry out this "method, a device with a disk seated on a rotating shaft is proposed, in which the coating material to be sprayed is applied to the rear side of this disk, which has a step formed as a throw-off edge, the disk being directed towards the workpiece Surrounded by compressed air flow and connected to a high voltage generator conductive * -

0 09 829/0 6-8.

bath

With this method and this device can the color throughput per unit of time compared to the reject, With spray guns operating electrostatically, it is essential can be increased. 'Nevertheless, it is also here in practice given an upper limit for the Parb throughput, since specified speed of the spray disc per approx. the length of the spray edge only a certain amount of paint can be sprayed and, for structural reasons, neither the diameter of the disks or their number of revolutions as desired can be increased. -

The object is now to be achieved with the invention are, with a given diameter of the spray disc and also given speed the! '' arb through at ζ pro Time unit to be increased even further. According to the invention This object is achieved in that a small distance behind the spray disc and concentric to it second, at least the same diameter and also rotating Spray disk is arranged, which at her with too spraying paint charged front one as a discharge; Schleuaerkaiite has trained level. .-. · - ■■

009 8 2 97 0 & 81

BATH ORIGINAL

With the invention it is possible to double the dye throughput with the same diameter and the same number of revolutions compared to the device according to the main patent. It has been shown in practice that the paint mist emanating from the adjacent throw-off edges does not interfere with one another either mechanically or electrostatically. This is in contrast to the usual electrostatic spray guns without Faraday ¹ see cage, in which nearby ionization cartridges have a strong potential influence and thus lead to a "reduced" spray effect.

The two spray disks or their throw-off edges can be supplied with color by a single, common color feed. but ils is also possible, and leads to very special advantages for the two spray disks provide separate, separately metered dye feeds. In the latter case two different materials can then be sprayed at the same time, with the ionization gap formed by the two edges of the pane intensively mixing of the two paint mists guaranteed. This possi-

9829/0681

BADORIGlNAt

J-iciucei-t opens up new ways of spraying Kehr! Component en-Hateri al, for example one of the sprinklers Lacquer to which a hardener is added to others, or mixed colors, such as metallic paints, then woftei from one edge the basic material, from the other Edge the material causing the metallic effect is sprayed. The embodiment with separate coloration can also be used to achieve a faster change of direction

be pulled, with each color then one of the paragraphs chi euderk & iiten assigned.

In order to achieve even larger working spaces Tdzw. With more diverse combination options, it is also possible to arrange a plurality of spray blades one behind the other with removal edges facing one another in pairs. . . _;

Other features, advantages and details of the The invention emerges from the description, the drawing and the claims. The drawing shows execution forms of the invention, for example, and show gwar?

BATH ORIGINAL,

16 5 2 33

b -

fig. 1 shows the spray head in cross section;

Fig. 2 shows a modification of the injection ■ head of Pig. 1 in cross section;

3 shows a section through the distributor ring of the spray head it from i'ig. 2 on a larger scale, Lind

Fig. 4 further embodiments of the invention and 5 proper spray head in the transverse = - " cut.

The spray head shown in Fig. 1 consists essentially of a first spray disc 10 and a second, coaxial and coaxial spray disc 11. The two spray discs 10 and 11 sit rigidly on the rotating shaft of a motor, not shown, for example a compressed air motor ^ the one running in the front a spray gun is housed. The disc 10 has a peripheral edge 12 and is provided on its rear side with a step on which a throw-off edge 13 is formed. The throw-off edge 13 is set back in the radial direction with respect to the peripheral edge 12. The second pane 11 has a marginal edge 14 and is provided on its front side with a step on which a KbB chieud edge 15 is formed. The edge

BADORI (SiNAi:

_ 7 ■ -

edges 12 and 1 * 4 as well as the centrifuge! cant en 15 and 15 have the same radial distance from the axis of rotation of the spray head. Between the two spray discs 10 and 11 a distributor ring 16 is arranged coaxially to it, the diameter of which is smaller than that of the discharge edges 13, 15 ″ of the distributor ring 16 a cross section substantially corresponding to an isosceles triangle, the tip 16a of which on the 'f

The axis of rotation of the spray head is directed. A feed pipe 17 parallel to the axis of rotation of the spray head and rigidly connected to the gun engages in the space between the two disks 10 xmä 11 and points with its nozzle opening 17a at the tip or inner edge 16a of the distributor ring 16.

As mentioned, the spray head sits on the rotating shaft of a motor and is driven by this with a speed | driven at dizzying speeds from 4,000 to 40,000 rpm « JSin Druekluftstrom is, as is known, against the spray - ^ - head directed in such a way that the spray head from the to Vferkstück leading compressed air stream is surrounded. Further is the spray head connected to a high-voltage generator

QOS829 / QSS 1

closed and is from "this. on a ^ r tension of for example Switch 50 to 100 kV. The outer, sharp ones Edges 12 and 14 of the spray head thus represent ionization edges represent.

"tf is now supplied via the pipe 17 years, so arrives this on the inner edge "16a of the rotating Distributor ring 16. Each edge 1ba divides the supplied ' The beam splits into two equal parts, which are on the ground the centrifugal forces that occur over the sloping flanks of the distributor ring 16 and the back side of the disc 10 or the front of the disc 11 is moved to the edges 13 and 15 and from these edges at high speed be thrown off radially outwards. The color material thrown off the edges 13 and 15 as a result of the platelets the impact on the air and the resulting strong deceleration immediately into the finest particles, so that the edges 12 and 14 bounded within the by Ring gap creates a Parbo Nebula, which emerges radially from the gap at low speed, without doing so to touch the edges 12 and 14. The edges 12

and 14 compressed air flowing around it detects the

00982S / 0581

BATH ORIGINAL.

stepping / i Parbiiebel, directs this in sighting: to "beaui's cnlagend en. ^{> r} he ': piece around and forms a Hinfi-mante!:, - .. ^f eleier the Parbneb.el wandering ^{to the T -} umiiitiltiina prevents "individual color particles from escaping to the outside" uas / sv / i see the charge edges 12 "uixa H on the one hand and the workpiece on the other as a result of the Hooiisparmun ^ aux ';; - built-in electrostatic j - ^T eld ionizes the M? arbneb el. when crossing. - "a = r through the edges T2 and 1: 4 placed, imaginary ^

Plane and convey the color particles along the field lines to the piece of work: Since the base only has to transport the already finely divided color particles and also takes off from the compressed air during this transport only relatively low field strengths are required.

üei deiii eri'indunj'sgex'iäaen dpritsicopr v / ird thus

■ "■■■ - ■ ^; I

the added color on two opposite ^

Firing edges 13 and 15 distributed, which are irrelevant cause a spray of paint from each other. " Opposite to a spray head with only one. Discharge the edge thus results with a smooth pane diameter

1652380

a diameter ^r at twice \ ert represents Abscnleuderkaata increased length. Since the maximum paint throughput depends directly on the length of the centrifugal sirte, the spray head according to the invention can be used to achieve a 100% increase in color penetration without adversely affecting the quality of the paint atomization, i.e. the purity of the paint mist produced. '

On Fig. 2 is a z.veite Äusf "ihrungpform shown erfindungsgemäSen of the spray head." Jiese Ausführungaform '"untersei'iei.aet from that described above only with respect to the ink supply and the formation of the distribution ring. Referring to FIG. Are namely α two paint feed pipes 1β and 19 are provided, the nozzle opening 18a of one feed pipe being directed towards the upper sloping flank, the nozzle opening 19a of the pipe 19 being directed towards the lower sloping flank of the distributor ring 16, onto the outer surface of the Distributor ring 16 is also fitted with a guide ring 20 which is coaxial with the distributor ring and can be adjusted so that the passage gap for the color can be set as desired.

009829 / 0S81

BATH ORIGINAL.

165239G

With the spray head according to Pig. 2 is it possible » of the two spray disks 10 and. 11 at the same time sV / ei to spray different materials, viie already Mentioned at the beginning, so for example when spraying of multi-component material through the pipe 18 of the paint, a hardener can be fed through the tube 19. The mixing of the lacfees with the hardener takes place only after Leaving the throw-off edges 13 »15 in. Ζ ^ rsprühter · ^ Shape. With this spray head it is also possible »to make extremely short laek changes. This pail will then the pipe 18 the one, for example black, the Tube 19 to the other, for example white lacquer material, assigned so that then quick varnish changes from white to black and vice versa are possible without having to clean the spray head when changing have to.

A particularly fine atomization of the Parbmateri- " than is achieved when the throw-off edges 13 »15 are radially corrugated. It is also possible, as on Pig.3 shown to provide radial millings 21 on the guide ring 20 so as to ensure a particularly uniform distribution of the - f

829 / Οδ ⁸

BATH ORIGINAL

16523SG

Reach paint on its way to the throw-off edges. These corrugations of the throw-off edges and / or the guide ring leave air in the paint material and produce, especially with viscous paints, a significantly improved surface quality of the applied paint Color film.

The spray head in FIG. 4 has the same basic structure as that of FIG. 2, but four throw-off edges are provided. For this purpose, a throw-off edge 22 is also formed on the rear side of the spray disk 11, and a further spray disk 23 with a throw-off edge 24 is also provided. Another distributor ring 25 with guide ring 26 is inserted into the space between the rear side of the disk 11 and the disk 23. The paint is supplied to the four centrifugal edges 13, 15, 22 and 24 via four outlet nozzles 18a, 18b, Möc and 18d of the dyeing tube 18 or, as not shown, via four separate, individually meterable color groups, the mode of operation of the spray head is obviously identical to that of the spray head of Fig. 2, although it is possible

00982970581

ORIGINAL BATHROOM

"—-13- ■

the liackdurcnsatz noon au further increase or .. at overall <sonderter Farbauf ^"<; .hruii £ ·, equilateral vi ^ r i'arb- or LaciCk.oniOone;, Teix individually versprünen In order to perfect the Lturcnmiocnung of.. In order to ensure that there are no four throwing edges, it is advantageous to provide all the spinning disks 10 and 23 with air intake bores 27, which penetrate the disks at an angle and at the undercut surfaces of the spraying edges 13, i

24 open. "-." · .- ■

On J? I £. b schließlicii an embodiment of the erfindungsgemäSen Spritzicopfes is shown for generating a spray circle of small diameter, wherein, on the same principle building, eight Absehleuderkanten 2b, 2y, 30, 31, 32, 33, 34 and 35 are connected in series. The arrangement is such that the facing pairs of edges 28 and 29, 30 μ

and 31, 32 and "33, 34 and 35 are the same as each other Have diameter, but the diameter of the edge pairs increase from front to back, so that the Edge pair 28, 29 the smallest, the edge pair 34> 35 has the largest diameter. To a flawless

009829 / DSS1 BAD ORIGINAL

To achieve mixing and ionization of the larb mist, the entire spray head is surrounded at a distance by a sleeve-like guide funnel 36, whose edge 36a facing the wedge serves as an ionization edge. In this case, the above ^T is thus arbnebel only electrostatically charged when leaving the guiding funnel 36th The paint supply can take place in such a way that it automatically adjusts itself to the most favorable amount of paint per throw-off edge. For this purpose, appropriately arranged and selected passageways to the individual throw-off edges, connected to overflow devices according to the cascade principle, can be provided.

009829/0581

BATH

Claims (7)

P A Ί 'üJ Ϊί-Ϊ.Α NSPR Ü G-H E M.) apparatus for electrostatically coating articles with liquid barren powdery coating material, with a sitting on a rotating shaft logs on whose rear side, which has a μ as off edge formed "level which is applied to be sprayed coating material, where-_ at the Disk surrounded by a compressed air stream directed towards the workpiece and conductively connected to a high voltage generator, according to patent ..... (patent application M 56 14-1 VIb / 75c), characterized in that a short distance behind the spray disk (10) and concentrically for this purpose a second, at least the same diameter and also rotating spray disc (11) is arranged, which has a step designed as a throw-off edge (15) on its front side charged with parbe to be sprayed. 009829 / 0S81 BATH ORIGINAL 2. Apparatus according to claim 1, characterized through a color switch in the form of a rotating, between, see the discs (10, 11) coaxially seated distributor ring (16) and at least one on the distributor ring (16) directed paint nozzle (16). -3 · Device according to claim 2, characterized in that that the two spray disks (10, 11) have separate, separately metered dye feeds (18, 19). 4. Apparatus according to claim 2 or 3, characterized in that that a guide ring (20) is adjustably arranged on the distributor ring (16). 5. Device according to one of claims 1 to 4, characterized gekennzeicnnet that the throw-off edges (la, 15) and / or the guide ring (20) are provided with radial distribution grooves (21). 6. Device according to one of claims 1 to 5 » characterized in that the spray disks (10, 11) 00-9 82 9/058 1 BAD ORIGfNAU - - 17 - with the spray edges (12, 15) laughing at the rear ^; opening Lui'tansaugbohrungen (27) -string · are. 7. Device according to one of claims 1 to .6, characterized in that the second spray disc (11) also has a step formed as a throw-off edge (22) on its rear side and that behind this second spray disc (11) and concentrically therewith an ' a third, at least the same diameter and also rotating Sprühscneibe (23) is arranged on her with to be sprayed! color charged front one as Has kick-off edge (24) formed step, wherein between the second (11) and the third (23) spray disc another distributor ring (25) with Leitx-ing (26) is arranged. S. Device according to one of claims 1 to f, gekennaeichnet by a plurality of spray disks connected in series with throwing edges (28,29; 30,31ί 32,335,34,35) facing one another in pairs and a guide cylinder (36) surrounding the spray head at a distance ₉ whose band edge (36a), which is attached to the workpiece, serves as a lonisatiönskarite. BAD ORfQINAt.