EP0568169B1 - Housing for a zinc bath - Google Patents

Abstract

The invention relates to a housing for a zinc bath (2) situated in a workshop transversely to the direction of conveyance of the workpieces. A support (10, 10') is situated at each of the narrow sides of the zinc bath (2) and two sliding doors (4, 4'), which are made up of individual door segments (6) and close in the vertical central plane of the zinc bath (2), extend between the supports (10, 10'). A cable hoist (16) pulls the uppermost door segments (6') upwards into the closed position and consequently also pulls the subsequent door segments (6', 6'',...) upwards; a chain hoist (17) acts on the lowermost door segment (6'''') and can raise the latter to a predetermined position so that the housing is either completely closed or the lower region is open as working region. <IMAGE>

Description

The invention relates to a zinc bath enclosure according to the preamble of patent claim 1.

Zinc baths for hot-dip galvanizing large workpieces can be 2 to 20 m long, 1 to 3 m wide and 1 to 3 m deep. They are arranged in a workshop either in the longitudinal direction or transversely to it. If a zinc bath is set up in the longitudinal direction of the workshop, it is usually no problem to immerse the workpiece in the zinc bath with the help of a traveling crane and then remove it again, even if the bath is surrounded by a housing, which serves to extract the vapors generated during the treatment in the zinc bath. For this purpose, it is only necessary to provide a longitudinal slot in the ceiling of the zinc bath enclosure, through which the wire cables of the overhead crane can be guided into the zinc bath enclosure from the outside inwards. The slot is expediently provided with sealing means such as bristle strips or rubber lips so that as little vapors as possible escape to the outside. Doors are provided in the end faces of the known zinc bath housing for introducing or removing the workpiece be opened. Since they open in the direction of transport of the overhead crane, they do not hinder the insertion of the workpieces.

Longitudinal galvanizing plants are relatively easy to house according to the principle mentioned above. However, they have the disadvantage that they require a considerable amount of space and therefore require long workshops. This is all the more true because not only must a zinc bath be provided in the workshop, but several pre-treatment baths and post-treatment stations must also be provided.

A second major disadvantage, however, is that these systems generally require long driveways with barges and thus there are idle times in the galvanizing bath. This is why cross-linked systems that are loaded with trolley tracks have prevailed in the galvanizing industry.

The above-mentioned housing system is not possible for baths arranged transversely to the hall direction. In these cases, housings are usually driven along with the galvanizing crane bridge. The greatest advantage of transverse systems, namely the time-saving loading of the zinc bath using trolley tracks arranged lengthways to the hall direction, is not possible. Especially when retrofitting old systems with housings due to legal regulations, major problems have arisen so far, since the existing conveyor systems can no longer be used and work processes have to be changed disadvantageously with regard to the capacity of the systems.

It is therefore an object of the invention to provide a zinc bath enclosure for a zinc bath arranged transversely to the transport direction of the workpieces in a workshop, which can be opened without difficulty for the insertion or removal of workpieces and can be closed without difficulty for the treatment of the workpieces immersed in the zinc bath, and this under the premise that the housing can be fed both by overhead cranes and by trolley tracks arranged lengthways to the hall direction.

To solve this problem, the characterizing features of claim 1 serve in conjunction with its preamble.

This ensures that only the front roller door needs to be opened by lowering it to bring in the workpieces in order to position a bulky workpiece with the overhead crane over the zinc bath. The front roller door is then closed again and the overhead crane can lower the workpiece into the zinc bath with the roller doors closed. After the treatment, the overhead crane lifts the workpiece out of the zinc bath, and after a short period of time during which excess zinc drips off, the rear roller door is opened to remove the workpiece.

Advantageous embodiments of the invention are the subject of dependent claims 2 to 8.

A cable or chain hoist engages not only on the top but also on the bottom roller door segment, which means that when the roller doors are closed, the bottom roller door segment can be raised in order to have access to the zinc bath and the workpiece which may be hanging above it.

In another embodiment of the invention, together with the lowermost roller door segment, the door segment located directly above it can also be raised in order to have greater freedom for access to the workpiece hanging above the zinc bath.

Figur 1

eine perspektivische Darstellung einer geschlossenen Zinkbadeinhausung;

Figur 2

die Zinkbadeinhausung aus Figur 1 mit geöffnetem, vorderen Rolltor;

Figur 3

eine schematische Darstellung einer Stirnseite der Zinkbadeinhausung von Figur 1; und

Figur 4

eine Teilansicht eines Teils des bei der Zinkbadeinhausung von Figur 1 verwendeten Haltegerüsts.

The invention is explained in more detail below with reference to figures; show it:

Figure 1

a perspective view of a closed zinc bath enclosure;

Figure 2

the zinc bath enclosure from FIG. 1 with the front roller door open;

Figure 3

a schematic representation of an end face of the zinc bath housing of Figure 1; and

Figure 4

a partial view of part of the scaffolding used in the zinc bath enclosure of Figure 1.

FIG. 1 shows a zinc bath housing 1 to be set up transversely to the transport direction in a workshop with two holding frames 10 and 10 ', which are arranged at a distance from one another. The holding structures 10 and 10 'are designed as U-shaped channels, through the interior of which the gases formed above the zinc bath can be extracted. The U is upside down. The holding structures 10 and 10 'are connected to one another under the workshop floor 19 by channels 13 and 13', which are therefore only indicated by dashed lines. On the inner sides of the holding frames 10, 10 ', side walls 12, 12' are arranged which close the clear passage of the holding frames 10 and 10 'and to which fastening and guide elements for the roller doors 4 and 4' are attached. In addition, doors 14, 14 'of a type known per se are provided in the side walls 12, 12', which provide access to the interior of the zinc bath housing 1.

Rolling gates 4, 4 'extend between the side walls 12, 12' and are closed from below upwards by means of cable pulls 16, 16 'and lifters 17, 17'. It can be seen in FIG. 1 that the roller doors 4, 4 'consist of individual door segments 6, 6', 6 '', 6 ''',6'''' are formed and each have a double bristle seal 8 at their upper ends, which extend over the entire length of the upper door segments 6 and through which the wire cables of a crane hook can extend into the interior of the zinc bath housing 1. When the housing is closed, the double bristle seals 8 of the two door segments 6 together form a flow channel, which is also suctioned off for better sealing.

The uppermost door segment 6 is pulled upwards by a cable pull 16, 16 ', which is guided forwards or backwards via a deflection roller 18. It is clear to the person skilled in the art how to arrange and redirect such a cable pull.

One can also see in the vicinity of the factory floor 19, expediently in the last door segment 6 ″ ″ window 20, through which an operator can look into the interior of the zinc bath housing 1.

FIG. 2 shows the zinc bath housing 1, which is open on one side, with the front roller door 4 open, which is lowered via the cable pull 16 and chain hoist 17. The individual door segments 6 are placed on the factory floor 19 from the inside out, the uppermost door segment 6 being the farthest away from the zinc bath 2. Since the same parts as in FIG. 1 are provided with the same reference numerals, the doors 14, 14 'in the side walls 12, 12' and other elements of the zinc bath housing can easily be seen. In addition, a closed railing 22 is shown, which is arranged around the zinc bath 2 to protect the operating personnel and, together with the closed housing, forms the bath enclosure. One can also see on the right side wall 12 'each a chain hoist 17 which attaches to the bottom gate segment 6''''in order to be able to pull it up. Details are explained with reference to Figures 3 and 4.

FIG. 2 also shows the state of the zinc bath housing 1 before the introduction of a workpiece. This is positioned in the longitudinal direction of the workshop and thus in the direction of arrow A with the roller shutter 4 open above the zinc bath 2 and lowered so far that the crane hook is located lower than the bristle seal 8 inside the zinc bath housing 1. In this state, the front roller door 4 can be closed again by the cable 16 pulling up the uppermost door segment. This takes the next door segment 6 'with it, which in turn pulls the next door segment upwards, etc., until the front roller door 4 is closed as shown in FIG. 1. The door segment 6 '' '' is raised with the separate chain hoist 17.

Figure 3 shows a section along the line BB in Figure 2 to illustrate how the individual door segments 6-6 '''' are pulled up. For this purpose, 12 guide tracks 26, 26'-26 '''' are arranged on the side wall, which are shown in the right part of FIG. Each of the guideways 26 ..., 26 '''' is provided for one gate segment 6, 6 '..., 6''''. Since the uppermost gate segment 6 is to be the furthest outside, its guideway 26 is the longest and extends from the vicinity of the workshop floor 19 to the very top near the upper end of the side wall 12. The inner guideway 26 'for the second gate segment 6 'is already significantly shorter and ends approximately before the horizontal deflection of the outermost guideway 26. The guideway 26''following inwards is even shorter, since the gate segment 6''guided in it is no longer pulled up completely, but instead hangs at the lower end of the second gate segment 6 '. The guideways 26'-26 '''' are therefore becoming shorter and shorter, ie they extend less and less upwards from the shop floor 19.

In the left part of Figure 3, the individual gate segments 6, 6 ', 6'',6''' and 6 '''' are shown as they are guided upwards in the guides 26-26 ''''. It is indicated how each one hooks the following gate segment into the lower end of a previous gate segment and is pulled upwards by the cable 16. To connect successive door segments 6 ', 6'', etc., pins arranged on the side edges can be used, which are gripped by shock-absorbed hooks of the next door segment. However, any other driver connection can also be suitable for this, for example shoulders, which run along the lower edge of each door segment and which are gripped by the lugs of the respectively following door segment.

Figure 3 also shows the raising or lowering of the bottom gate segment 6 '' '' by a chain hoist 17 which engages the bottom gate segment 6 '' ''. This serves to have access to the zinc bath 2 when the zinc bath housing 1 is still closed, in order to position or treat the workpiece.

FIG. 3 also shows two suction openings 24 provided in the side wall 12, which lead into the interior of the holding frames 10 and, when the zinc bath housing 1 is closed, suck off the gases formed therein through the channels 13, 13 '. It is clear that, for this purpose, extraction fans should be arranged in the channels 13 and 13 ', respectively, which extract the gases.

FIG. 4 shows a section of the zinc bath housing according to FIG. 2, namely - seen in the direction of arrow A - from the left holding frame 10 'with the left side wall 12'. One recognizes the channel 13 'provided in the holding frame 10', which opens into the suction opening 24 at the upper end. The side wall 12 'is carried by a stand 28. In the illustration according to FIG. 4, the door segments 6 are lowered and it can be seen how the chain hoist 17 acts on the lowest door segment 6 '''' in order to pull it upwards according to the left part of FIG. 3. The chain hoist 17 is guided upwards and outwards via deflection rollers 18. At the ends of the chain hoist 17 engage chain wheels which are driven by a motor, not shown.

FIG. 4 also shows a schematic view of the guideway 26, which leads the uppermost gate segment 6 to the very top. It is pointed out that the second holding frame 10 'is constructed symmetrically and that guideways 26 and cable pulls 16 and chain hoists 17 are arranged on each holding frame 10 or 10'.

Claims (8)

1. Housing for a zinc bath (2) situated in a factory hall transversely to the direction of transport of the workpieces, characterised in that on each of the narrow sides of the zinc bath (2) is provided a support frame (10, 10'); that two sliding gates (4, 4') extend between the support frames (10, 10'), the gates being composed of individual gate segments (6) and closing in the vertical middle plane of the zinc bath (2); that a cable control mechanism (16) pulls the uppermost gate segments (6) up to the closing position and thereby pulls with it the following gate segments (6', 6'', ...); that a chain control mechanism (17) engages the lowermost gate segment (6'''') and may lift it to a predetermined position, so that the housing may be either fully closed or the lower region may be opened as a working region.
2. Housing for a zinc bath according to claim 1, characterised in that a segment stop (32) may be moved into the path of movement of the gate segments (6, 6', 6'', 6''') and on it may be seated the upper gate segments (6, 6', 6'', 6''') lifted by the cable control mechanism (16).
3. Housing for a zinc bath according to claim 1 or 2, characterised in that on the upper edges of the uppermost gate segments (6') are provided bristle seals (8) which extend along the whole length of the sliding gates (6) and consequently across more than the whole width of the zinc bath (2).
4. Housing for a zinc bath according to any one of claims 1 to 3, characterised in that on the lateral edges of the gate segments (6, 6', ... 6'''') are provided at the bottom carrier bolts and at the top hooks, and laterally are provided guiding rolls which run in guideways (26', ... 26'''') fixed on the support frames (10, 10').
5. Housing for a zinc bath according to any one of claims 1 to 4, characterised in that a separate guideway (26', ..., 26'''') is provided for every gate segment (6, 6', ... 6'''').
6. Housing for a zinc bath according to any one of claims 1 to 5, characterised in that the guideway (26', ..., 26'''') for the lowermost gate segment (6'''') is arranged nearest to the zinc bath (2) and the guideway for the uppermost gate segment (6) is arranged farthest therefrom, so that, when the housing (1) for the zinc bath is closed, the gate segments (6) overlap each other from above and outside inwardly and down.
7. Housing for a zinc bath according to any one of claims 1 to 6, characterised in that windows (20) are provided in at least some of the gate segments (6'''').
8. Housing for a zinc bath according to any one of claims 1 to 7, characterised in that the support frames (10, 10') are made as exhaust channels and are provided with exhaust openings (24) which, when the sliding gates (4) are closed, open to the inside of the housing (1) for the zinc bath.

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