EP1518608B1 - Device for surface coating of small articles - Google Patents

Abstract

The surface coating device consists of a drum (60) in the form of a hollow cylinder with a partition wall (67a, 67b) dividing it into two symmetrical drum chambers (61, 62) of equal dimensions to receive dosed amounts of small parts through opposite apertures (73) in the drum jacket (63). The apertures can be closed by caps.

Description

The invention relates to a single-drum coating device for surface coating of small parts referred to in the preamble of claim 1. Art.

Various surface coating devices are known. The coating of the small parts takes place here in the heap by means of a rotating drum, which is immersed either for receiving the coating material in a coating tank (see. DE 196 13 927 and DE 102 09 908 C1 ) or in which the coating agent is sprayed (see. DE 34 20 859 C2 ).

After the coating has taken place, the coating drum is set in rapid rotation in order to spin off excess coating material by means of the centrifugal force and to even out the coating on the surface of the small parts.

Two criteria limit the maximum filling volume of the coating drum.

On the one hand there is a risk for larger filling volumes that the small parts are distributed unevenly within the drum, resulting in unattainable or difficult to control imbalances during the spinning process.

On the other hand, the drum is to be dimensioned so that the drop height of the small parts is as small as possible both when loading and emptying the drum.

These conditions lead to a restriction of the drum diameter and thus the volume of the small parts to be coated.

The present invention is based on the object to provide a device with a drum, which better meets the conditions mentioned and also allows for smaller systems, a larger throughput.

After the proposal according to claim 1, this object is achieved. It is a device in which the consisting of a hollow cylinder with horizontally arranged drum axis drum is divided into two equal-sized, rotationally symmetric chambers which superimposed opposite, arranged symmetrically to the drum axis openings with the small parts and can be pivoted by means of the drum arranged flaps are closable.

By dividing the drum into two symmetrical drum chambers, a more uniform filling of the drum is possible, whereby imbalances are avoided, especially with larger filling quantities.

In addition, these drum chambers can be filled or emptied via their provided in the drum shell openings at a suitable angular position of this drum so that the introduced as bulk material or auszubringenden small parts are subject to only a very small drop height.

According to claim 1, the openings of the drum shell are closable with flaps, which are arranged pivotably between the drum lids.

A particularly advantageous embodiment of the partition and the flaps is specified with claim 2. Here, the partition consists of two on both sides of the drum axis diametrically arranged radial sections, which are followed by arcuate extending to the drum shell sections. The flap here also has an arcuate portion which corresponds to the arcuate portion of the partition and which applies to the outside in the open state of the flap. The arcuate portion of the flap is in this case dimensioned so that it closes the opening of the drum in the closed state.

A simple and controllable with little effort flap is the subject of claim 3, according to which the arcuate portion of the flap is supported on both sides by two circular segment-shaped side parts which are pivotally mounted on the drum lids, wherein the pivot axis of the flap parallel to the drum axis and close to the outer periphery the drum runs.

Is, as indicated by claim 4, the pivot axis rotatably connected to the flap, it can be rotatably connected to this located on the outside of the drum cover pivot lever, with which the flap closed or opened by rotation of the drum in one or the other direction becomes. For this purpose, only a displaceable spool is to be provided, on which runs the pivot lever upon rotation of the drum.

Under the action of the centrifugal force, the flaps close automatically upon rotation of the drum. However, to keep the door clearly in an open or closed position, is provided between a pivot lever and drum cover arranged compression spring according to claim 5, wherein pivot lever and compression spring are formed in the manner of a toggle lever.

Advantageously, the flap can be provided according to claim 6 with a slide extending over its width, which gently guides the small parts when filling or emptying the drum chamber at low drop height.

Important for the two-part according to the invention drum is their exact filling, as uneven levels in the drum chambers have an imbalance result.

For this purpose, a loading and metering device is provided according to claim 7, wherein each of the two drum chambers is assigned in each case a feed chute, which is displaceable on a support and guide rail parallel to the drum axis. This loading and metering device is associated with a weighing and filling station according to claim 8, with which the two feed chutes are filled with precisely metered, equal amounts of small parts.

The proposed drum with the invention is suitable both for a compact system in which the drum by means of a transport slide only in two stations is movable.

The first station serves to charge or empty the drum, while the second station, which has a coating basin which can be raised against the drum, serves both for coating and for centrifuging the small parts located in the drum.

The components required for such a system, such as rotary drive, splash guard, storage pallets and reservoir for coating agent are the subject of claims 10 to 13.

However, the same coating drum is also suitable for a multi-drum circulating coating system, as described in detail in DE 102 09 908 C1 is described.

• Beschickungsstation zur Befüllung der Trommeln;
• Beschichtungsstation, in welcher die umlaufende Trommel in ein Beschichtungsbad getaucht wird;
• Abtropfstation, in welcher überschüssiges Beschichtungsmaterial bei langsamer Trommeldrehung abtropft und in einer Wanne aufgefangen wird;
• Schleuderstation, in welcher die Trommeln in schnellere Drehung versetzt werden, wodurch eine Vergleichmäßigung der Beschichtung erfolgt und noch vorhandenes, überschüssiges Beschichtungsmaterial abgeschleudert wird; sowie
• Entleerstation, in welcher die Trommeln bei geringer Drehzahl entleert werden.

In this case, a number of coating drums is provided, which can be transported successively by means of a longitudinal conveyor according to claim 14 in the following stations:

• Feeding station for filling the drums;
• Coating station in which the rotating drum is immersed in a coating bath;
• Draining station, in which excess coating material drips off at slow drum rotation and is collected in a tub;
• Spinning station, in which the drums are set in a faster rotation, whereby a homogenization of the coating takes place and still existing, excess coating material is thrown off; such as
• Emptying station, in which the drums are emptied at low speed.

In accordance with claim 15, as in the o. G. Specified patent specification, provided a transport device for returning the emptied drums.

Figur 1

perspektivische Darstellung einer Eintrommelbeschichtungsanlage mit erfindungsgemäßer Beschichtungstrommel,

Figur 2

schematischer Längsschnitt der Vorrichtung längs der Linie II-II in Figur 4,

Figur 3

schematische Aufsicht der Vorrichtung gemäß Figur 2,

Figur 4

schematische rechte Ansicht der Vorrichtung gemäß Figur 2 und 3,

Figur 5

schematischer Längsschnitt einer Mehrtrommel-Umlaufanlage längs der Linie V-V in Figur 7,

Figur 6

Aufsicht der Anlage gemäß Figur 5,

Figur 7

linke Ansicht der Anlage gemäß Figur 5 und 6,

Figur 8

perspektivische Darstellung einer erfindungsgemäßen Beschichtungstrommel, Klappe geschlossen,

Figur 9

perspektivische Darstellung der erfindungsgemäßen Beschichtungstrommel ohne einen der beiden Trommeldeckel,

Figur 10

Radialschnitt der Trommel gemäß Figur 8 und 9,

Figur 11

Seitenansicht der Trommel gemäß Figur 10,

Figur 12

perspektivische Darstellung der Trommel entsprechend Figur 8, jedoch mit geöffneter Klappe und schematischer Darstellung eines Steuerschiebers,

Figur 13

Seitenansicht der Trommel gemäß Figur 12 mit strichpunktiert angedeuteten Klappen und

Figur 14

Radialschnitt der Trommel mit Beschickungsschütte und Auffangpalette zur Darstellung des Materialflusses.

The object of the invention is described below by means of embodiments which are partly schematic in the drawings are explained in detail. In the drawings show

FIG. 1

perspective view of a single-drum coating machine with coating drum according to the invention,

FIG. 2

schematic longitudinal section of the device along the line II-II in FIG. 4 .

FIG. 3

schematic plan view of the device according to FIG. 2 .

FIG. 4

schematic right view of the device according to FIGS. 2 and 3 .

FIG. 5

schematic longitudinal section of a multi-drum circulating system along the line VV in FIG. 7 .

FIG. 6

Supervision of the system according to FIG. 5 .

FIG. 7

left view of the plant according to FIGS. 5 and 6 .

FIG. 8

perspective view of a coating drum according to the invention, flap closed,

FIG. 9

perspective view of the coating drum according to the invention without one of the two drum covers,

FIG. 10

Radial section of the drum according to FIG. 8 and 9 .

FIG. 11

Side view of the drum according to FIG. 10 .

FIG. 12

perspective view of the drum accordingly FIG. 8 , but with open flap and schematic representation of a spool,

FIG. 13

Side view of the drum according to FIG. 12 with dash-dotted lines and flaps

FIG. 14

Radial section of the drum with loading chute and collecting pallet for displaying the material flow.

To illustrate the applications and the operation of the drum according to the invention are first based on the FIGS. 1 to 7 two coating systems explained in which the drum can be used in an advantageous manner.

The exact structure of the drum according to the invention is then based on the FIGS. 8 to 14 explained.

The very compact single-drum coating device 10 has a machine stand 11, on which a transversely displaceable coating drum 12 is arranged. This coating drum 12 is freely rotatably mounted in a drum transport slide 15, with which the drum 12 can be moved from a loading and unloading in the 12 'indicated with the coating station. In order to be able to set the coating drum 12 or 12 'in rotation, coupled drive motors 19, 20 are provided on the machine stand 11 of the drum 12a or 12a', which are assigned pressing devices 21 and 22 on the opposite side. To transport the drum 12 in the position 12 'and vice versa are the drive and pressing devices 20, 22 and 19, 21 axially apart, so that the drum is freely movable in the transverse direction.

In the filling station, in which the drum 12 is, feed chutes 25, 26 are provided, which are transversely displaceable on a supporting and guide rail 27 in the dot-dashed positions. Each one of the two chutes 25 and 26 is, as below with reference to the FIGS. 8 to 14 is explained associated with one of the two drum chambers.

The filling of the feed chutes with equal amounts of small parts is carried out in the Figures 3 and 4 dot-dashed positions. After filling the drum chambers, the drum 12 is moved to the position 12 ', wherein in the manner explained below, the drum openings are closed.

Below the drum 12 'is located in the coating station, a coating tank 16 which is raised for the purpose of coating against the rotating in slow rotation drum 12. The drum wall, preferably the drum shell, are perforated, so that coating agent can get into the interior of the drum and wets the small parts inside the drum with coating agent. The coating tank 16 is connected via connecting hoses 24 to a reservoir 23, so that by means of a level controller for a sufficient amount of coating agent in the coating tank 16 can be provided.

After coating, the coating tank 16 is lowered and the drum 12 'initially set in slow rotation, so that excess coating agent drip off can. This is followed by a rapid rotation of the drum 12 ', whereby on the one hand achieves a homogenization of the coating under the effect of centrifugal forces, and on the other hand, excess coating agent is thrown off. In this case, the splash guard 14 situated above the coating drum 12 'is lowered, so that the thrown off coating material does not get into the housing 13 covering the entire apparatus.

Before the return of the drum from position 12 'by means of the drum transport slide 15 in the position of the drum 12, the splash guard 14 must be raised again in the upper position shown in the drawing.

In position 12, the flaps are now opened in a slow rotation, so that the coated small parts can fall into the located below the drum 12 pallet 17.

By means of a pallet conveyor 18, the pallet 17 is moved to the dot-dashed position 17 'to be fed from there for post-processing a furnace or other drying plant. Despite a fairly large drum volume, the single-drum coater is in accordance with the FIGS. 1 to 4 quite compact. Advantageously, the device is completely housed with the exception of two openings for loading and unloading by means of the housing 13. The openings in the area of the feed hoppers 25, 26 or the collecting pallet 17 can also be equipped with flaps, which largely avoids air exchange with the surrounding air and thus leakage of solvent of the coating material.

However, the cycle time for the coating in this compact apparatus is limited by filling and discharging in position of the coating drum 12 and coating and centrifuging the position 12 '.

As far as shorter cycle times are required, a multi-drum circulating coating device, as used in FIGS. 5 to 7 shown schematically and in DE 34 20 859 C2 is described in detail.

In this device, a number of coating drums 41a to 41n are provided, wherein the various operations take place successively in different stations.

The two chambers of the drum 41a are filled via chutes 48 in the manner described with small parts. By means of a lifting beam transport device, not shown, the drum is further transported in position 41b and immersed in a coating tank 22 with slow rotation.

In position 41c, excess material drips off with slow rotation. The material is collected with a drip tray 43.

In position 41d, the coating drum is set at a higher speed, so that excess coating material is thrown off under the effect of the centrifugal forces and collected by means of the lower and upper splash guard hoods 44, 45 comprising the drum 41d.

In position 41f, the drum flaps are opened so that the coated material rotates slowly emerge down and can be collected by means of a pallet 46.

The emptied drums are returned to the starting position via the positions 41g to 41n.

The core of both systems and object of the present invention is in detail in the FIGS. 8 to 14 Coating drum 60 shown. The coating drum 60 has the shape of a hollow cylinder, which consists of a drum shell 63 and drum covers 64, 65 on both sides. Drum caps 64, 65 and / or drum shell 63 are perforated to allow entry of coating material into the interior of the drum.

To drive and transport the drum 60, a drive and transport axle 66 is provided, which passes through the interior of the drum and on both sides of the drum cover 64 and 65 projects beyond.

The interior of the drum is divided by means of a partition 67 into two equal-sized, rotationally symmetrical drum chambers 61 and 62. The partition wall consists of two diametrically arranged on both sides of the drive and transport axis 66 diagonal sections 67a (radial sections) and this subsequent and reaching to the drum shell 63 arcuate sections 67b.

The drum shell 63 is interrupted on opposite sides by two openings 73. These openings 73 are provided with pivoted around the dash-dotted axes S flaps, as shown in the in FIG. 9 Open position shown above in the closed position shown below can be pivoted.

Each flap 68 has bilateral circular segment-shaped plates 68a, which are connected to each other via the arcuate portion 68b, with which the drum opening 73 is closed. In the opened state, the arcuate portion 68 b abuts on the outside of the arcuate portion 67 b of the partition 67. When closed, this arcuate portion 68b complements the arcuate portion 67b to a complete closure of the opening 73. Finally, a chute 68c is provided on the flap 68 as a filling and emptying aid, whose operation is based on FIG. 14 will be explained below.

The flap 68, more precisely, the circular segment-shaped plates 68a of the flap 68, is / are rotatably connected to a pivot axis 69, which surrounds the in FIG. 8 dash-dotted axis S is rotatable. Fixedly connected to this pivot axis 69 is a pivot lever 70 which is located on the outside of the drum cover 64. Its free end is connected to one end of the compression spring 71 which is connected at the other end to a bolt 72 of the drum cover 64. Swivel lever 70 and compression spring 71 are arranged in the manner of a toggle lever such that the pivot lever 70 and thus rotatably connected with it flap 68 in two positions, namely the open and the closed position, is fixed, as this is especially the illustrations in FIG. 10 . 12 and 13 make clear.

This simple toggle assembly allows easy control of the flaps. For this purpose, only one coaxial with the drive and transport axis 66 is arranged against the drum cover 64 or displaceable from this slide spool 74 necessary. This spool is arranged and controllable such that its outboard pin 74a is located in the advanced position of the spool 74 by way of the free end of the pivot lever 70. Upon rotation of the drum 60 in the direction of the arrow D, the pivot lever 70 runs on the bolt 74 a, whereby the flap 68 is opened or closed due to the rotation of the coating drum 60.

An essential advantage of the coating drum 60 designed according to the invention is, in addition to the uniform filling capability of the drum chambers 61 and 62, the gentle filling or emptying.

In FIG. 14 a coating drum 60 is shown, the drum chamber 61 is loaded via the dot-dash line feed chute 25 with small parts, not shown, present in the form of bulk material. The small parts located in the loading chute 25 slide in this case at the lowest possible drop height on the chute 68c of the flap 68 and along the diagonal portions 67b of the partition 67 into the drum chamber 61. The path through which the small parts pass is indicated by the arrow B.

With the second chamber 62, the flap 68 is shown in the open position, the emptying is illustrated. In this case, the small parts located in the drum chamber 62 slide approximately along the arrow A through the chamber opening 73 located at the bottom onto the pallet 17 shown in phantom.

Both when filling and when emptying only relatively low drop heights, which is extremely important for a gentle handling of the present in the form of bulk small parts.

LIST OF REFERENCE NUMBERS

10

Single-drum coater

11

machine stand

12

Coating drum, when filling or emptying

12 '

Coating drum, during coating or centrifuging

13

casing

14

Splash guard

15

Drum transfer slider

16

coating tank

17

palette

18

Pallet transport means

19

drive

20

drive

21

pressing device

22

pressing device

23

reservoir

24

connecting hoses

25

loading chutes

26

loading chutes

27

Support and guide rail

40

More drum circulating coating apparatus

41

a to n coating drums

42

coating tank

43

drip tray

44

lower splash guard

45

upper splash guard

46

palette

47

Pallet transport means

48

coating Schütte

49

Support and guide rail

50

reservoir

51

connecting hoses

60

coating drum

61

first drum chamber

62

second drum chamber

63

drum shell

64

drum lid

65

drum lid

66

Drive and transport axle

67

partition wall

67a

Diagonal section of the partition

67b

arcuate section of the partition

68

flap

68a

circular segment-shaped sheet metal

68b

arcuate section of the flap

68c

slide

69

swivel axis

70

pivoting lever

71

compression spring

72

spring mounting

73

openings

74

spool

Claims (15)

1. Drum coating device (10) for the surface coating of small parts, comprising a coating drum with a partially perforated wall and at least one closable loading and emptying opening and also a rotary drive, a loading and emptying station, a coating station with a coating basin, into which the coating drum can dip, and a transport device for transporting the coating drum from the loading and emptying station to the coating station, characterised in that the coating drum (60) comprises a hollow cylinder with a drum casing (63), drum caps (64, 65) on both sides and a drive and transport axle (66) arranged horizontally and coaxially in the hollow cylinder, which coating drum (60) is divided into two equal-sized, rotationally symmetrical drum chambers (61, 62) by means of a separating wall (67) running for example along the diagonal, and in that the drum casing (63) has openings (73) located opposite one another and arranged symmetrically in relation to the drive and transport axle (66), which openings can in each case be closed by means of a flap (68) arranged pivotably between the drum caps (64, 65).
2. Device according to claim 1, characterised in that the separating wall (67) consists of two radial sections (67a) arranged diametrically opposite one another on both sides of the drive and transport axle (66), and of sections (67b) adjoining said radial sections and running in a curved manner as far as the drum casing (63), and in that the flaps (68) in each case have a curved section (68b) corresponding to the curved section (67b) of the separating wall (67) as a mirror image thereof in relation to the radial separating wall section (67a), which curved section (68b) bears against the outer side of the curved section (67b) of the separating wall (67) in the open state of the flap (68) and closes the opening (73) of the coating drum (60) in the closed state of the flap (68).
3. Device according to claim 2, characterised in that the curved section (68b) of the flap (68) is carried on both sides by two metal sheets (68a) in the shape of a segment of a circle which are mounted pivotably on the drum caps (64, 65), wherein the pivot axle (69) of the flap (68) runs parallel to the drive and transport axle (66) and close to the outer circumference of the coating drum (60).
4. Device according to claim 3, characterised in that the pivot axle (69) is connected to the flap (68) so as to rotate therewith, in that a pivot lever (70) placed on the outer side of the drum cap (64) is connected to the pivot axle (69) so as to rotate therewith, and in that the pivot lever (70) is assigned a control slide (74) which can be pushed forwards in such a way that the flap (68) is opened when the coating drum (60) is rotated in one direction and is closed when the coating drum is rotated in the opposite direction.
5. Device according to claim 4, characterised in that the free end of the pivot lever (70) is connected to a pressure spring (71) which is fixed at the other end to the outer side of the drum cap (64), wherein the pivot lever (70) and the pressure spring (71) are arranged in the manner of an angled lever.
6. Device according to one of claims 1 to 5,
   characterised in that the flap (68) is provided with a chute (68c) which extends over the width thereof for guiding the small parts to be filled in or emptied.
7. Device according to one of claims 1 to 6,
   characterised in that a loading and metering device is provided above the opening (73) of the coating drum (12; 60), which loading and metering device consists of at least two loading chutes (25, 26) which can be displaced parallel to the drive and transport axle (66) on a carrying and guiding rail (27) and by means of which portioned quantities of small parts can be filled into the drum chambers (61, 62).
8. Device according to claim 7, characterised in that the loading and metering device is assigned a weighing and filling station, by means of which the two loading chutes (25, 26) are filled with precisely metered, equal quantities of small parts.
9. Device according to one of claims 1 to 8, characterised in that the coating drum (12) can be displaced by means of a drum transport slide (15) out of a station used for loading and into a station used for coating, in which there is provided a coating basin (16) which can be lifted towards the coating drum (12').
10. Device according to claim 9, characterised in that in each case a connectable rotary drive (20, 22; 19, 21) for the coating drum (40) is provided both in the loading station and in the coating station.
11. Device according to claim 9 or 10, characterised in that a spray protection hood (14) is arranged above the coating drum (12') located in the coating station.
12. Device according to claim 9, 10 or 11, characterised in that a pallet (17) for the depositing of the coated small parts is provided below the coating drum (12) located in the loading and emptying station, which pallet can be transported by means of a pallet transport device (18) to an oven or the like.
13. Device according to one of claims 9 to 12, characterised in that the coating basin (16) is connected to a reservoir (23).
14. Device according to one of claims 1 to 7, characterised by a plurality of coating drums which can be transported by means of a longitudinal conveyor into the following stations in succession:

    loading station

    coating station

    dripping station

    spinning station

    emptying station.
15. Device according to claim 14, characterised by a transport device which serves for returning the emptied drums.

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