EP1044725A2 - Apparatus for spraying a liquid on workpieces - Google Patents

Abstract

The suction unit of the spraying unit (76) has a capacity corresponding to five to twenty times the amount of air supplied t the spray heads (84) to produce the fluid mist (14). Both a section (34,38) of the first housing wall (18) and second housing wall ( lying above the associated opening (106,108), and also a section (36,40) of the first and second walls lying below the openings constructed as hollow wall sections. The free ends of the hollow wall sections adjacent to the openings support screen elements (114,116).

Description

The invention relates to a device for spraying of flat workpieces, especially sheet metal, with a Liquid, e.g. a lubricant according to the preamble of claim 1.

Such devices are particularly in connection with press lines used to press or to spray deep-drawn sheets with a lubricant. This will cause cracking and drawing marks in the workpiece avoided and will reduce the deformation necessary force and protection of the pressing tools reached.

Such a device is known from EP 0 060 375 A2 known. There the suction device becomes relatively smaller Suction power operated, so that spray fans emerge from the spray heads due to air movements not be disturbed. This reduces the effectiveness the suction device when setting Flow conditions within the housing of the spray device.

In such known devices, although prevents a housing surrounding the spray head arrangement, that large amounts of fog escape into the environment. By however, the passage window for the workpieces enters liquid mist from that on neighboring machines and on the footprint as an increasingly thicker film precipitates what in terms of keeping the Breathing air and keeping the installation area clean potential risk of accident is disadvantageous.

The use of a suction device within such The device is known from EP 0 060 375 A2. There the suction device with relatively low suction power operated to allow spray fans out of the spray heads emerge, are not disturbed by air movements. This reduces the effectiveness of the suction device the setting of defined flow conditions within the housing of the spray device and thus its efficiency when extracting fog.

The present invention is therefore intended to provide a device further developed for spraying flat workpieces be that on the passage windows of the housing certainly no liquid mist escapes.

According to the invention, this object is achieved by a device with the features specified in claim 1.

In the device according to the invention by the Through openings adjacent cavity wall sections liquid mist reaching the passage openings suctioned with a defined suction power. This keeps the environment clean.

Advantageous developments of the invention are in the subclaims specified.

A device as reproduced in claim 2 sucks both above the conveying level of the workpieces escaping liquid mist as well as below the Conveying mist emerging from the workpiece conveyor level in the area the passage openings of the housing. This is particularly so then an advantage if the workpiece is both Sides is sprayed here.

The development of the invention according to claim 3 allows it, the size of the suction effects at the passage openings adjust as needed by using each suction slot adjusted at least one aperture body.

The development of the invention according to claim 4 allows it, the width of the suction slot in the longitudinal direction of the slot to vary so in different places of the suction slit either despite the unequal geometry of the vacuum pathways still a constant To ensure suction power, or suction power in To vary the longitudinal direction of the suction slot, e.g. in Edge areas to suck or increased suction power in such slot areas, which are reduced by internal Installation of the housing better against liquid mist are shadowed.

The development of the invention according to claim 5 allows it, the panel body at the same time as a contact surface or centering aid to be used for the workpiece ends.

In a device according to claim 6 one has for maintenance purposes good access to the inside of the case.

It is then ensured according to claim 7 that a Large dimension connection opening to one Assigned suction shaft fixed to the housing, wherein one automatically with a closed cavity wall section Sealing at the joint between the cavity wall section and receives a suction shaft.

In a device according to claim 8 aspirated liquid mist still entrained liquid parts deposited before the extracted air gets into the blower of the suction device.

A liquid separator as specified in claim 9 is particularly well suited for effective separation of oil droplets.

With the development of the invention according to claim 10 it is ensured that the accumulating in the liquid separator Liquid together with residual liquid, the is obtained inside the housing, is disposed of.

The development of the invention is according to claim 11 with regard to lossless negative pressure of the suction slits formed by the cavity wall sections advantageous.

It is in the geometry specified in claim 12 advantageous that they can be easily bent by bending sheets can produce and that you automatically a flat interface towards a frame-fixed suction shaft, which along with an adjacent flat side surface the suction shaft forms a detachable sealing point, without any significant effort being made here ought to.

The development of the invention according to claim 13 allows an adjustment of the suction shafts fixed to the housing Workpiece conveying direction in parallel direction.

With the development of the invention according to claim 14 will cause shading of the spray heads Mist cone scored against the interior of the case without that there is a risk of being on the shielding plates form larger drops, which then fall onto a workpiece could and there the uniformity of the liquid application affect.

It is achieved according to claim 15 that on the shield forming drops on both sides from the middle of the housing in the conveying direction be carried out.

According to claim 16, a seal of the interior of the housing is obtained against direct exposure to liquid mist from the entry-side passage window of the housing to the exit-side passage window.

The training according to claim 17 is in view a good edge seal between the shielding plate and Housing is an advantage.

Figur 1:

einen longitudinalen vertikalen Mittelschnitt durch eine Station zum Besprühen von Blechen mit Schmiermittel;

Figur 2:

eine Aufsicht auf zwei Blendenkörper, die zum Einstellen der Breite eines konturierten Absaugschlitzes der in Figur 1 gezeigten Station dienen;

Figur 3:

eine Aufsicht auf die außenliegende Wand eines Saugschachtes der Station nach Figur 1; und

Figur 4:

eine Aufsicht auf die innenliegende Wand einer hohlwandigen Tür der Station nach Figur 1.

The invention is explained in more detail below using an exemplary embodiment and with reference to the accompanying drawing. In this show:

Figure 1:

a longitudinal vertical central section through a station for spraying metal sheets with lubricant;

Figure 2:

a plan view of two diaphragm body, which are used to adjust the width of a contoured suction slot of the station shown in Figure 1;

Figure 3:

a view of the outer wall of a suction shaft of the station of Figure 1; and

Figure 4:

a top view of the inner wall of a hollow-walled door of the station of Figure 1.

In Figure 1, 10 denotes a housing as a whole, in which sheet metal pieces 12 from above and below with a Lubricant mist cone 14 or 14 'brought into contact become.

The housing has a top wall 16, an inlet side Transverse wall 18, an outlet-side transverse wall 20, parallel to the direction of conveyance of the sheets (indicated by arrow 22) extending side walls 24 and a bottom wall 26, which at the same time as a collecting tub for not from the sheet metal pieces 12 entrained litter oil is used.

Transport rollers are located in the side walls 24 of the housing 10 28 stored, which is a horizontal funding level for specify the sheet metal pieces 12. The transport rollers 28 are driven by a common toothed belt 30 which the output gear 32 of a not shown Drive motor works.

The entry-side transverse wall 18 consists of two pivotable Doors 34, 36, which are mirror images of through the transport rollers 28 arranged conveyor plane are.

The exit-side transverse wall 20 is a mirror image of the Cross wall 18 constructed from two doors 38, 40.

Since the structure of the doors is symmetrical, it is enough to Construction of a single door, namely door 34 more precisely to describe.

The door 34 (see FIG. 4) has an outer wall 42 and one inner wall 44 spaced therefrom from the interior of the housing upper ends of outer wall 42 and inner wall 44 are connected by an edge wall 46. To the front or ends of the door 38 to be thought behind the plane of the drawing, 40 is that through outer wall 42, inner wall 44 and edge wall 46 channel formed by end walls 48 in the longitudinal direction of the channel locked.

As can be seen from the drawing, the inner wall 44 an upper wall portion spaced more from the outer wall 50 and just a little bit from the outer wall 42 spaced lower wall section 52. The lower ends of outer wall 42 and wall section 52 define one Suction slot 54. The wall sections 50 and 52 are through an oblique central wall section 56 connected, such that the transverse cross section of the door 34 one Rectangle with a right-angled triangle and corresponds to the beak carried by the latter.

In the wall section 50 there is a close to its edges extending connection opening 58 is provided.

The door 34 is over at its upper outer end a hinge 60 is pivotally attached to the housing 10. The closed position of the doors is shown in FIG. Each of the doors can hinge around the associated one be pivoted away from the housing to access the Preserve the interior of the housing.

When the door 34 is closed is on the outer surface of the Wall section 50, the side surface of a suction shaft 62 in which one of the connection openings 58 corresponds Connection opening 64 is provided. The ends the suction shaft 62 are associated with support plates 66 and Pin / slot guides 68 carried by the housing 10. In this way, you can so the suction shaft 62 adjust in the conveying direction of the sheets 12 that when closed Door 34 a gap seal between the wall section 50 and the suction shaft 62 is obtained. Possibly. can on the remaining edges of the suction shaft 62 or the wall section 50 an elastomeric sealing frame 69 (Figure 3) are placed.

Through this connection between the inside of the door 34 and the suction shaft 62 is on the one hand the pivotability the door 34 ensures, on the other hand when closed Door a flow-tight connection from the suction shaft 62 guaranteed to the inside of the door 34.

For the other doors 36 to 40 are assigned analogously Suction shafts are provided, and the suction shafts are over Lines 70, 72 with the input of an electrostatic filter 74 connected. Its output is one with the input Suction blower 76 connected.

Inside the housing 10 is between the side walls 24 extending a hollow profile 78 is provided, which limited a compressed air channel 80. The hollow profile 78 carries via solenoid valves 82 spray heads 84, which under regular Distance along the hollow profile 78 are distributed.

A second hollow profile 86 is thermally conductive with its underside placed on the top of the hollow profile 78. It delimits a lubricant channel 88. The latter is connected by hoses 90 to injectors 72 which correspond to injection nozzles used in diesel engines and serve the that supplied via the lubricant channel 88 Atomize lubricant finely. The one from the compressed air duct 80 via the solenoid valves 82 to the spray heads Air supplied serves to support the nebulization and the mist cone generated by the injectors 92 14 to shape, in particular to flatten.

The injection nozzles 92 extend with their end section through matching openings in a section 96 an angled shield 98. The section 96 of the shield plate 98 is inclined so much that larger drops of lubricant that grow together of fog droplets on the shielding plate, below Drain gravity down along the sheet. An inclination ensuring such a flow a sheet is used in the present description and referred to in the claims as the run-off angle. At the The exemplary embodiment considered here is the run-off angle about 20 °.

The section 96 of the shield plate 98 extends until against the wall section 56 and settles in one bevelled end section 100, which is parallel to the wall section 56 of the door 38 runs.

The shield plate has immediately upstream of section 96 98 a further under opposite discharge angle arranged section 102, which extends up to the wall section 56 extends the door 34 and there again has small end portion 104, the positive abuts the wall section 56.

The geometry shown in the drawing shows the axis of the spray heads 84 perpendicular to the section 96 of the shield plate 98 and thus closes with the conveyor level the sheets 12 form an angle of approximately 70 °, so that the fog cone 14 with one of the conveying direction 22 opposite speed component on a underlying sheet metal 12 strikes.

The geometric relationships in the lower section of the Housing 10 are mirror images of those just explained Conditions in the upper section.

To ensure effective suction power through the doors 34, 36 and 38, 40 limited passage windows of the To be able to adjust the housing 10 have the outer wall 42 and the inner wall 44 lower end portions 110 and 112, each opposite to each other under about 25 ° to the conveying plane of the sheet metal pieces 12 are employed. On each of the end sections 110, 112 there is a panel body 114 and 116 slidably arranged in the conveying direction and by screws 118, 120 in each set Position fixable. This limits the diaphragm body 114, 116 each the effective suction slot, the ends of the doors adjacent to the conveyor level 34 to 40 is present.

As can be seen from Figure 2, you can see the free edge contour the aperture body 114, 116, e.g. one middle edge edge section exactly in the longitudinal direction Provide 122 at the ends of the diaphragm body increasingly recessed edge sections Connect 124, 126. In this way, limit the aperture body 114, 116 together a suction slot 128, the Width to the side edges of the passage window increases. This way you can make any worse Pressurization at the side ends of the suction slot 128 compensate or a reinforced Specify suction at the ends of the suction slot 128.

A floor pan 130 is provided in the electrostatic filter 74, which collects the lubricant deposited there. The lowest point of the bottom wall 130 is via a drain line 132 with the through the bottom wall 26 of the housing 10 lubricant sump formed. The Do not dispose of lubricant that has been taken from the metal sheets can be done at a central point namely when the bottom wall 26 runs out.

The spray system described above works as follows:

If a piece of sheet metal to be sprayed reaches one by one predetermined distance arranged in front of the fog cones 14 Position transmitter 134, the spray heads 84 are activated and create the fog cones 14. Moving forward of the sheet metal piece 12 on the transport rollers 28 then both sides of the sheet metal piece 12 with lubricant mist busy. Reaches the rear end of the piece of sheet metal 12 one behind the by a predetermined distance Fog cone 14 arranged position transmitter 136, the Mist generation by the spray heads 84 ended.

Both when switching on and when switching off the spray heads 84 lubricant mist is already being generated or still is generated, although no piece of sheet metal in the fog cones 14 stands. Is a sheet metal piece 12 in the fog cones 14, is part of the fog directed at the sheet metal surfaces reflected from the sheet surface. It forms with it lying overall between the two shielding plates 98 Clear out a lubricant mist. Part of this Lubricant mist is looking through the passage window 106 and 108 to exit to the environment.

But since the doors 34 to 40 are designed as hollow chamber elements are and via the suction shafts 62 with the electrostatic precipitator 74 and the suction blower 76 are connected, will emerge between the doors 34 and 36 and 38, 40 aspirated amounts of fog before being sucked in the surroundings escape. In the electrostatic filter 74 that is Lubricant contained in the sucked-back mist is separated and from there the one formed by the bottom wall 26 Collecting pan fed.

In this way, pollution of the environment is Station cleared by escaping lubricant mist.

The suction power of the suction fan is preferably 76 approximately ten times the volume of the spray heads 84 fed Air volume. This ensures that no air containing lubricant mist from the Housing 10 emerges. A lower limit for suction power of the suction fan 76 is at five times the Seen the volume of air supplied, an increase in Suction power of the suction fan 76 over twenty times of the volume of compressed air supplied would be unnecessary air suck from the area around the housing.

For maintenance purposes, the doors 34 to 40 can be moved around their Hinges 60 to be given away. The upper doors 38 and 40 can and in the open position by lever 138 can be locked, which is pivoted through these doors and with housing-fixed mounting bolts (not shown) work together.

The bottom wall 26 also collects oil to be sprayed Pieces of sheet metal 12 with different edge contours by gaps between such sheet metal pieces 12 flows through.

In an alternative embodiment, extend the connection openings 64 and 58 do not cover the whole Cross section of the suction shaft 62 or the one facing it Wall section 50 of the inner wall 44 of the hollow-walled door 34. Facing each other with the door 34 closed frontal connecting walls that the wall section 50 and the suction shaft 62 in this embodiment complete, there is a round connection opening executed near one of the end walls 48. The Diameter of these two aligned connection openings is about the size of the narrow side of the rectangular connection opening 64 of the related with Figures 3 and 4 embodiment described.

Claims (18)

Device for spraying workpieces (12), especially of sheets, with a liquid, in particular a lubricant, with a spray head arrangement (84) with pressurized fluid is applied and from this a moving liquid mist (14) manufactures with a conveyor (28 to 32) for moving the workpieces (12) on the spray head assembly (84) over and with a spray area surrounding housing (10), which in a first wall (18) a first passage opening (106) and in a second wall (20) a second passage opening (108) for workpieces (12), at least one section the first wall (18) and / or a section of the second Wall (20), each of the corresponding passage opening (106, 108) is adjacent to the wall, as a cavity wall section is formed and the cavity wall sections (34 to 40) are connected to a suction device (76), characterized in that the suction power of the suction device (76) five to twenty times that Air volume corresponds to the spray heads (84) for generation of the liquid mist (14) is supplied. Device according to claim 1, characterized in that both one above the assigned passage opening (106, 108) lying section (34, 38) of the first Housing wall (18) and the second housing wall (20) as well as one under the passage openings (106, 108) lying section (36, 40) of the first housing wall (18) and the second housing wall (20) as a cavity wall section is trained. Device according to claim 1 or 2, characterized in that that the passage openings (106, 108) adjacent free ends of the cavity wall sections adjustable Wear the panel body (114, 116). Device according to claim 3, characterized in that at least some of the diaphragm bodies (116, 118) the free edge is contoured. Device according to claim 3 or 4, characterized in that that the diaphragm body (114, 116) in one Plane lying around 20 to 40 °, preferably about 30 °, are inclined to the conveying plane of the workpieces (12). Device according to one of claims 1 to 5, characterized characterized in that the cavity wall sections (34, 36, 38, 40) around a direction parallel to the conveying plane and to the conveying direction vertical axis (60) are pivotable. Apparatus according to claim 6, characterized in that the cavity wall sections (34 to 40) on their to Side facing the inside of the housing each with one wide connecting opening extending along its length (58), which are provided with an opposite, connection opening having the same geometry (64) a fixed suction shaft (62) essentially is connected in a fluid-tight manner when the cavity wall sections (34 to 40) are in a closed position. Device according to one of claims 1 to 7, characterized by one upstream of the suction device (76) Liquid separator (74). Device according to claim 8, characterized in that the liquid separator (74) is an electrostatic filter is. Device according to claim 8 or 9, characterized in that that the liquid separator (74) one Liquid collection pan (130) having a Discharge pipe (132) communicates that to a floor pan (26) of the housing (10) leads. Device according to one of claims 1 to 10, characterized characterized in that the hollow wall sections (34 to 40) towards the passage openings (106, 108) rejuvenate (56). Device according to claim 11, characterized in that the cavity wall sections (34 to 40) a transverse Have cross-sectional shape that is essentially one Rectangle with one in the direction of the adjacent passage opening (106, 108) placed on this, preferably right triangle. Device according to one of claims 6 to 12, characterized characterized in that the suction shafts (62) via guides (68) are adjustable in the conveying direction (22). Device according to one of claims 1 to 13, characterized characterized in that an end portion of the spray heads (84) each passed through a shielding plate (98) which is at such a drain angle to the horizontal it is employed that it is depressed by growing together Droplets of droplets formed under the influence of gravity flow away. Device according to claim 14, characterized in that the shield plate (98) two in opposite Sections running at a drain angle (96,102). Device according to claim 14 or 15, characterized in that that the shielding plate (98) up to the cavity wall sections (34 to 40) is performed. Device according to claim 16, characterized in that that the shielding plates (98) one each to the neighboring Hollow wall section (34 to 40) folded parallel Have end portion (104). Device according to one of the preceding claims, characterized in that the suction power of the Suction device (76) about ten times that Air volume corresponds to the spray heads (84) for generation of the liquid mist (14) is supplied.

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