EP0387535B1 - Method of and installation for producing foundry moulds - Google Patents

Description

The invention relates to a method for producing foundry molds in successively arriving mold boxes, each box being moved upwards out of its feed path by a model plate carrier arranged in a transfer device and taking a filling frame into a filling station, lowered after filling and through move the transfer device under a compression station, then drive it up, compress it and lower it again, separate it and move it away via a discharge path.

In molding plants with ongoing model plate changes, it is known, for example, from DE-OS 37 13 937, the filling and the compression of the mold boxes to be carried out at spatially separate stations. As a result, a molding box can be filled and another molding box compressed at the same time, which increases the throughput of this molding system accordingly. However, the time required for completing the impression unit, i.e. for stacking the model plate carrier, the mold box and the filling frame, as well as for the subsequent separation of these parts, is still high. In addition, the known system requires an auxiliary vessel, the volume of which approximately corresponds to the molding space formed from the molding box and filling frame, and because of this auxiliary vessel, large lifting movements of the model plate carrier, that is to say, work with correspondingly complex lifting tables, are required.

The present invention is therefore based on the object of specifying a method and a device for producing foundry molds with the features mentioned at the outset, which is distinguished on the one hand by a higher hourly output and on the other hand by a low outlay on equipment.

From a procedural point of view, this object is achieved according to the invention in that the filling frame is separated from the box after the compression process, but before the box is placed on its discharge path, and is returned separately to the filling station.

This results in the advantage that the next box, ready for filling, is completed with the filling frame while starting up in the filling station and can be filled directly without additional lifting movements. The stacking of the model plate carrier, molding box and filling frame and driving up to the filling station thus takes place in one and the same operation.

Furthermore, there is the advantage that the mold box is already separated from the filling frame during the downward stroke in the compression station when it is placed on its discharge path.

In terms of the device, the invention is realized in that a further transfer device for the filling frame is arranged above the transfer unit for the model plate carrier. This transfer unit preferably has adjustable holding elements which can be moved into a holding position or out of this path into a rest position during the lifting movement of the filling frame in its path. This ensures that the filling frame in the filling station can be removed from the transfer device upwards, but after the filling process can be lowered past the transfer device downwards and that it can equally pass the transfer device in the compression station, but after the compression process it is held by it and is separated from the molding box.

While the transfer device for the filling frame can be designed as a linear exchange unit or also as a swivel arm, a rotary changer, in particular a turntable, is recommended for the transfer unit of the model plate carrier. This transfer unit also handles the transport of the boxes between the incoming and outgoing roller conveyor.

Fig. 1

eine Seitenansicht der Formanlage;

Fig. 2

eine Draufsicht auf die Formanlage;

Fig. 3

eine vergrößerte Draufsicht auf die Umsetzvorrichtung für den Füllrahmen;

Fig. 4

eine vergrößerte Detailzeichnung der Umsetzvorrichtung in der Draufsicht und

Fig. 5

einen Querschnitt längs der Linie V-V in Figur 4, jedoch in Halteposition.

Further features and advantages of the invention emerge from the subclaims and the following description of an exemplary embodiment with reference to the drawing; shows:

Fig. 1

a side view of the molding system;

Fig. 2

a plan view of the molding system;

Fig. 3

an enlarged plan view of the transfer device for the filling frame;

Fig. 4

an enlarged detail drawing of the transfer device in plan view and

Fig. 5

a cross section along the line VV in Figure 4, but in the holding position.

As shown in FIG. 1, a filling station 2 and a compression station 3 are mounted in a common frame 1. Roller conveyors 4 and 5, which extend perpendicular to the plate plane, serve to move the empty mold boxes 6 or to remove the molded mold boxes 7. Both roller conveyors are in the area fold the side of the filling station and the compression station so that the mold boxes can be moved freely in the vertical direction. This method is carried out by means of a lifting table 8 assigned to the filling station and a lifting and external table 9 assigned to the compression station and therefore of a stronger design.

A rotary table 10 is mounted in the center between the two lifting devices. It contains two receptacles offset by 180 ° for the model plate carriers 11 and 12.

A transfer device 13 for the filling frame 14 is arranged above the turntable 10 and coaxially with it. It transports the filling frame 14 back to the filling station 2 after the compression process. Their structure will be explained in more detail later.

Finally, FIG. 1 shows in the upper area of the filling station a sand container 15 which is arranged above the lifting table 8 and which has a flap closure or the like at the bottom in order to fill the sand into the molding box and filling frame.

In the compression station 3, a pressure vessel 16 is indicated, with which the filled sand is compressed in a known manner by a pressure pulse. However, it is within the scope of the invention instead to choose a mechanical or any other compression.

The system functions as follows:
An empty molding box 6 runs into the filling station in a known manner via the roller conveyor 4. The lifting table 8 lifts the model plate carrier 11 out of the turntable 10, takes over the molding box 6 from the roller conveyor 4 and then the filling frame 14 from the transfer device 13 and drives these stacked parts close to the underside of the sand container 15. While the model plate carrier is being filled 11, molding box 6 and filling frame 14 existing molding space with sand, the roller conveyors 4 and the holding elements of the transfer device 13 are pivoted outward so that the molding unit can be lowered back onto the turntable 10 unhindered.

For an explanation of the holding elements between the transfer device 13 and the filling frame 14, reference is made to FIGS. 4 and 5. It can be seen there that the transfer device consists of two parallel pivot arms 13a and 13b, the spacing of which is somewhat greater than the length of the filling frame 14. For the releasable connection of the two parts, horizontally pivotable holding elements 17 and 18 are mounted on the swivel arms, which correspond to projections 19 and 20 of the filling frame.

Fig. 4 shows these holding elements in their pivoted-back rest position, in which the filling frame can be moved vertically undisturbed.

5 shows a holding element 18 pivoted into its holding position, in the bore 18a of which a guide pin 20a of the projection 20 engages from above. Thus, the filling frame is held in a form-fitting manner, but can be moved upwards by the lifting ram 8.

The holding elements 17 and 18 are actuated, for example, by a pneumatic cylinder which is integrated in the sequence control of the system. Another drive can also be used instead.

After the filling process, the holding elements 17 and 18 are therefore in the position shown in FIG. 4, and the roller tracks 4 are also pivoted away, so that the lifting table 8 can move down with the entire molding unit. The molding unit is then moved through the turntable 10 through 180 ° into the compression station and at the same time the transfer device 13 brings the filling frame 14 previously removed from the compressed molding box back into the filling station, while a new, empty molding box arrives there.

The filled molding unit is now moved upwards from the lifting and shaping table 9, the roller tracks 5 and the holding elements of the swivel arms 13a and 13b located in the compression station being pivoted outwards. The impression unit is then pressed against the pressure vessel 16 so that the pressure pulse can be triggered.

During this time, the holding elements 17 and 18 move into their holding position in the compression station and the roller conveyors 5 are also pivoted inwards again. As a result, when the lifting table 9 is lowered, the filling frame 14 is first held by the pivot levers 13 and separated from the molding box 7. The molding box is then taken up by the roller conveyors 5, so that finally only the model plate carrier 12 moves back into its seat in the turntable 10.

At about the same time as the lifting movement described in the compression station, the lifting movement described at the beginning is repeated in the filling station with the next molding box, which is completed with the filling frame which has previously been pivoted out of the compression station.

The functional sequence described shows that the separate filling frame transport by the transfer device 13 makes it possible to stack the model plate carrier, mold box and filling frame on top of one another and to fill them on the one hand and to compress and stack the parts mentioned in one stroke movement, always simultaneously a molding box in the filling station and a molding box in the compression station are treated. The molding plant according to the invention achieved therefore significantly higher hourly output than in the known case. In addition, it is characterized by unproblematic and in principle proven construction elements.

It is equally suitable for alternating lower and upper boxes in a normal molding machine as in the exemplary embodiment as well as for working with two different models in a double molding machine.

Claims (15)

1. A method of producing foundry moulds in successively incoming moulding boxes, in which each box is moved upwards out of its supply conveyor by a pattern plate support arranged in a transfer device and, taking with it a filling frame, passes into a filling station, is lowered after filling and conveyed by the transfer device to below a compacting station, is then lifted into that compacting station, compacted and lowered again, separated and conveyed away by means of a removal conveyor,
   characterised in that
   after the compaction operation but before the box (7) is set down on its removal conveyor (5), the filling frame (14) is separated from the box (7) and returned separately to the filling station (2).
2. A method according to claim 1,
   characterised in that
   after the compaction the filling frame (14) undergoes only a small part of the lowering movement with the box (7), is then stopped and conveyed approximately horizontally to the filling station (2) and finally is brought into the filling position by the next box (6) being lifted.
3. A method according to claim 1 or 2,
   characterised in that
   the filling frame (14) is moved approximately at the same time as the transfer of the pattern plate support (11, 12).
4. An apparatus for carrying out the method according to any one of the preceding claims,
   characterised in that
   above the transfer unit (10) for the pattern plate supports (11, 12) there is arranged a further transfer device (13) for the filling frame (14).
5. An apparatus according to claim 4,
   characterised in that
   the transfer device (13) for the filling frame (14) has adjustable holding elements (17, 18) which, during the stroke movement of the filling frame (14), can be moved into the path of the filling frame into a holding position or out of that path into a rest position.
6. An apparatus according to claim 5,
   characterised in that
   the holding elements (17, 18) in the holding position correspond with lateral projections (19, 20) on the filling frame (14).
7. An apparatus according to any one of claims 4 to 6,
   characterised in that
   the transfer device (13) for the filling frame (14) is constructed in the form of a swivel arm.
8. An apparatus according to claim 7,
   characterised in that
   the swivel arm is mounted in its centre between the filling station (2) and the compacting station (3).
9. An apparatus according to any one of claims 4 to 8,
   characterised in that
   the transfer unit (10) for the pattern plate supports (11, 12) is constructed in the form of a turntable.
10. An apparatus according to claim 9,
    characterised in that
    the transfer unit (10) for the pattern plate supports (11, 12) is arranged on a common shaft with the transfer device (13) for the filling frame (14).
11. An apparatus according to any one of claims 4 to 10,
    characterised in that
    the incoming boxes (6) are transported on a conveyor (4) that terminates in the filling station (2) and the outgoing boxes (7) are transported on a conveyor (5) that starts from the compacting station (3).
12. An apparatus according to claim 11,
    characterised in that
    the boxes (6, 7) are transported between the incoming and outgoing conveyors (4 and 5) by the transfer unit (10).
13. An apparatus according to claim 11 or 12,
    characterised in that
    the two conveyors (4, 5) run in parallel and displaced relative to one another.
14. An apparatus according to any one of claims 4 to 13,
    characterised in that
    the transfer device (13) for the filling frame (14) has its own pivot drive.
15. An apparatus according to any one of claims 4 to 13,
    characterised in that
    the transfer unit (10) for the pattern plate supports (11, 12) and the transfer device (13) for the filling frame (14) have a common drive.

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