EP0047507A1 - Moulding machine for making flaskless moulds - Google Patents

Abstract

The invention aims to increase the production of molding machines for the production of boxless farms, in which the pressing forces are introduced horizontally into the molding sand. Furthermore, the invention aims that, depending on the metallurgical conditions, one or the same molding machine can produce bale strands with vertical parting lines or those with horizontal parting lines. This is achieved according to the invention in that a plurality of mold boxes (3. 4) are aligned with a common center line in a horizontal guide (2) lying in the pressing and extending direction between the press ram (12) and a swiveling press device and are displaceable in the guide . A model support plate (21) is provided between the individual mold boxes, which can be retracted and extended when the mold boxes are pulled apart. A tipping device (10) is arranged at the outlet of the machine, which either allows the pressed bales to pass in an unchanged joint position, or with which the bales pressed in pairs can be tilted by 90 °.

Description

The invention relates to a molding machine for producing boxless molds with a mold box with its center line lying horizontally on both sides, the one opening of which can be closed by a horizontally acting ram and the opposite opening can be closed by a swiveling press device, and in which at least one of the pressing surfaces facing each other a model half can be attached, as well as with a stacking device onto which the finished pressed bale can be pushed horizontally through the molding box with the help of the press ram after the pressing device has been swung out. In these machines, the pressing forces act on the molding material in the horizontal direction. This results in one-piece molded bales, in the end faces of which a mold cavity is pressed in, so that a molded bale strand with vertical parting lines is formed when pushed onto the stacking device (see e.g. DE-PS 12 11 760).

This method has significant advantages over that in which the pressing forces act vertically in the molding sand. Here you need two bale halves for each shape, i.e. 2 n shape halves for n shapes. With horizontal production direction, you only need n + 1 shaped bales. This results in an enormous reduction in molding sand requirements and a correspondingly high saving in energy and time. After the molds have been filled and the melt solidified, the hardened molds are, as is known, broken up and the castings are probed. The forasand tubers are then ground, the recovered sand is dedusted and cooled by spraying with water. After drying, the sand that has been reprocessed in this way is transported to the molding shop. This process requires a considerable amount of energy and time, which increases proportionally with the total amount of molding sand required in a foundry. The gronse: The main advantage of the molding machine with horizontal production direction described at the beginning is that it requires almost half the molding sand compared to machines with vertical production direction.

Various proposals for increasing the performance of molding machines with a horizontal pressing direction have already been made. For example, in the extrusion molding system according to DE-PS 24 05 371, the mold box carrier is designed as a rotary table with step drive, and there are several mold boxes arranged in pairs opposite one another, so that several compression and ejection stations are formed which are actuated simultaneously. This machine therefore requires a considerable amount of construction work, since each pressing station requires its own pressing device and each ejecting station needs its own ejecting device. The insertion of cores should also be complicated, which can only be done in an intermediate station. Because of the centrifugal force that occurs during rotation, the cores must be additionally secured, e.g. to be nailed. There must also be some play on a turntable. This in turn results in a higher risk of the mold halves not clogging up congruently. There is a higher offset and thus a higher risk of rejects.

In the molding machine according to DE-AS 25 23 645 for stacking pairs of molded bales with a horizontal parting line, two mold cavities are arranged in two sliding frames, which are displaced in opposite directions transversely to the horizontal pressing direction. One slider produces lower, the other upper mold halves. The machine also has two pressing devices which act on both sides of an abutment plate pushed between the slides. The joints between the abutment plate and the mold cavities in the pressing position are sealed by means of inflation seals. After the pressing process, the slides are pushed into the ejection positions, and the two shaped bales are pushed onto a tilting device and tilted 90 ° around a horizontal axis transversely to the direction of ejection. The upper half of the bale is then raised in the feed station and the associated lower half of the bale is moved underneath. Finally, the shaped bales thus added are pushed in pairs across a common transport device and brought into the casting station. Even the transverse movement of the sliding plates, be it horizontal or vertical, requires a certain amount of running play, which increases the risk of an unacceptably large misalignment. Even more, however, the many movements of the boxless halves of the bale in the horizontal and vertical directions with changes in direction have to increase the risk of misalignment and thus the waste.

Similar to this machine, the molding machine according to DE-OS 22 28 806 is equipped with two double molding boxes which can be moved transversely to the horizontal pressing direction, but which are arranged at such a distance from one another that a pressing device acting in both horizontal directions can be accommodated between them, so that the molding sand is compacted from both sides. This creates four bale strands in pairs and in parallel. For stacking shaped bales with a horizontal parting line, two bale halves with a vertical parting line are also added outside the machine, rotated by 90 ° by means of a tilting device and pushed onto a transport system transversely to the pressing direction. Because of the inevitable running play of the two double-sided mold boxes and the large displacement of the mold bales, a correspondingly large offset is also unavoidable in this machine.

Finally, with the USA-PS 36 95 339 a working with two vertical pressing stations molding machine has become known, in which two mold halves are pressed separately, the Shaped boxes are then tilted in opposite directions by 90 °, pushed together in an axial guide with the aid of additional drive devices for each box and pushed out with a special ejection device. However, this machine cannot produce bale strands with a horizontal parting line.

The present invention has for its object, while avoiding the shortcomings of the machines described above, to increase the performance of molding machines with a horizontal pressing direction and to design them so that optionally bale strands can be produced with a horizontal parting line of the bale halves. Despite the superiority of the machines with a horizontal pressing device in terms of production times, molding sand requirements and the like. These machines are particularly unsuitable for the production of molds for flat, relatively narrow castings when high demands are placed on a homogeneous structure. This applies e.g. for brake disks, clutch disks, and the like cast from wear-resistant hard cast alloys. If these are cast upright, an inhomogeneous crystalline structure solidifies mainly under the influence of gravity, which causes different coefficients of friction on the working surfaces of these machine elements. Up to now, therefore, one had to use molding machines with a vertical pressing direction only for such needs.

The invention consists in that at least one further molding box which is open on both sides and the first molding box is arranged in alignment between the press ram and the pressing device, all molding boxes are movable in a common horizontal guide lying in the pressing and extending direction along the molding box center line, and that between two adjacent mold boxes a model support plate is provided, the cross section of which corresponds to the clear cross section of the mold boxes, and which - in a manner known per se - can be extended and retracted when the mold boxes are pulled apart.

According to the invention, several shaped bales are produced with only one set of pressing tools. A particular advantage of the invention is that the pressed mold bale halves are already added inside the machine, so that a minimum of misalignment is ensured. With the combination according to the invention of axially displaceable mold boxes and retractable and extendable model support plates, this machine is particularly suitable for coating the models outside the molding machine. In the case of the machines explained above with regard to the prior art, such methods would be extremely difficult to use, if at all.

In order to achieve the alternative manufacturing possibility, in a further development of the invention, a tilting device is arranged at the outlet of the machine, which can either pass the pressed molded bales in an unchanged joint position, or can be tilted by 90 ° with the molded bales pressed in pairs.

One could object to the invention that the costs for the production and storage of the models would increase many times over if only one and the same mold were to be produced. For a large foundry, this should hardly matter. But you can also - as before - with

one pair of model halves can be used if, according to a further proposal of the invention, different model halves are alternately attached to the pressing tools and to the model support plates.

• Fig. 1 den Längsschnitt durch eine Formmaschine mit zwei Formkästen in der Arbeitsstellung "Pressen",
• Fig. 2 die Formmaschine nach Fig. 1 in der Arbeitsstellung "Ausschieben".
• Fig. 3 Die am Ausgang der Formmaschine angeordnete Kippvorrichtung zum Stapeln von Ballensträngen mit vertikalen Trennfugen in der Passierposition,
• Fig. 4 die Kippvorrichtung nach Fig. 3 zum Stapeln von Ballensträngen mit horizontaler Trennfuge in der Ladeposition,
• Fig. 5 die Kippvorrichtung nach Fig. 4 nach Schwenkung um weitere 90 in der Entladeposition,
• Fig. 6 den Längsschnitt durch eine Formmaschine analog Fig. 1 und 2 mit drei Formkästen in der Preßposition,
• Fig. 7 die Draufsicht auf die Ein- und Ausfahrvorrichtung für die Modelltragplatte.

In the following, the invention is explained using some exemplary embodiments. The associated drawings show in

• 1 shows the longitudinal section through a molding machine with two molding boxes in the "pressing" working position,
• Fig. 2 shows the molding machine of FIG. 1 in the "push out" working position.
• 3 shows the tilting device arranged at the exit of the molding machine for stacking bale strands with vertical parting lines in the passing position,
• 4 shows the tilting device according to FIG. 3 for stacking bale strands with a horizontal parting line in the loading position,
• 5 shows the tilting device according to FIG. 4 after pivoting by a further 90 in the unloading position,
• 6 shows the longitudinal section through a molding machine analogous to FIGS. 1 and 2 with three molding boxes in the pressing position,
• Fig. 7 is a top view of the entry and exit device for the model support plate.

1 denote the machine bed with the dovetail guides 2, in which the horizontally lying mold boxes 3 and 4 are axially displaceably mounted. At the top, each molding box has an opening 7, 8, above which the molding sand funnels 9, 10 are attached. At the left end of the machine bed 1, the press cylinder 11 is attached, the press ram 12 has penetrated into the molding box 3. At the opposite end there is the press device 13 with a box-shaped press head 14 which can be expanded by internal pressure and which is fastened by means of a swivel arm 16 to the shaft 17 of the servomotor 18 and can be both axially displaced and swiveled by the latter.

The servomotor 18 itself is fastened on a frame 20 which surrounds the outlet opening 19 and which at the same time serves as a molding box stop when the mold bales are pushed out (FIG. 2). Between the two molding boxes 3, 4 is the model support plate 21, the cross section of which corresponds to the clear cross section of the molding boxes 3, 4 and which are also designed to be spreadable by internal pressure. It is axially displaceable (floating) between the mold boxes in the direction of the mold box center line, in order to be able to avoid different pressurization from one side, and is moved in and out transversely to the pressing and extending direction with the actuating cylinder 52 shown in FIG. 7.

The molding box 3, 4 can be coupled to the press ram 12 and the press head 14 by means of mechanical couplings 50, 51, so that they can be pushed back and forth by the latter for the various work cycles. 27a, 27b and 28a, 28b denote the model halves which belong to one another and which here have different contours.

• 1. Einfahren der Modelltragplatte 21 mit den Modellhälften 28a, 28b,
• 2. Ankuppeln des Formkasten 4 an das Preßwerkzeug 14 (NB. der Formkasten 3 ist noch vom vorausgegangenen Arbeitsgang an den Preßstempel 12 gekuppelt),
• 3. Schließen der beiden Formkästen 3,4 durch axiales Verschieben,
• 4. Einbringen des Formmaterials, gegebenenfalls mit pneumatischer Unterstützung,
• 5. Abkuppeln der Formkästen und gleichzeitige Druckbeaufschlagung des Preßstempels) der Preßvorrichtung sowie der Hodelltragplatte,
• 6. Ankuppeln und Auseinanderzichen der beiden formkästen 3,4,
• 7. Ausfahren der Modelltragplatte 21,
• 8. gegebenenfalls Kerne einlegen,
• 9. Abkuppeln des Formkasten 4, Ausfahren und Ausschwenken des Preßkopfes 14,
• 10. Verschieben der Formkästen 3,4 bis zum Anschlag am Rahmen 20,
• 11. Abkuppeln des Formkastens 3 und Ausschieben beider Formballen durch die Ausgangsöffnung 19 zum Formballenstrang 29 und Rückführen der am Preßstempel 22 angekuppelten Formkästen 3,4 in ihre Ausgangspositionen, wobei der Formkasten 4 - nach Erreichen seiner Ausgangspositionvom Preßstempel 12 abgekuppelt wird,

In the starting position, the two molding boxes 3, 4 have moved apart, the model support plate 21 is located outside the machine. The individual work stages run as follows, with the respective. End positions are secured by appropriate stops:

• 1. Retracting the model support plate 21 with the model halves 28a, 28b,
• 2. Coupling the molding box 4 to the pressing tool 14 (NB. The molding box 3 is still coupled to the pressing die 12 from the previous operation),
• 3. Closing the two molded boxes 3, 4 by axial displacement,
• 4. Introducing the molding material, if necessary with pneumatic support,
• 5. uncoupling of the mold boxes and simultaneous pressurization of the press ram) of the pressing device and of the model support plate,
• 6. Coupling and drawing apart the two molded boxes 3, 4,
• 7. Extending the model support plate 21,
• 8. insert cores if necessary,
• 9. Uncoupling the molding box 4, extending and swiveling the press head 14,
• 10. Move the molding boxes 3, 4 to the stop on the frame 20,
• 11. Uncouple the mold box 3 and push out both mold bales through the outlet opening 19 to form bale strand 29 and Returning the mold boxes 3, 4 coupled to the press ram 22 to their starting positions, the mold box 4 being uncoupled from the press ram 12 after reaching its starting position,

6 shows a molding machine which is basically the same as that shown in FIGS. 1 and 2, but with three molding boxes 3 ', 4', 4 "between which a number of model support plates 22 ', 21" which is equal to the number of molding box joints are arranged. Since these are expandable and are subjected to the same pressure as the pressing tools 11 'and 13', it is ensured that the molding material in the middle molding box 4 'is compressed as well as in the molding boxes 3' and 4 "at the ends the number of mold boxes can be expanded as required.

When the molded bales are pushed onto the bale strand 29, they pass through a tilting device 30 which is explained in more detail with reference to FIGS. 1, 3, 4 and 5.

The tilting device 30 consists of a support plate 35 driven by the hydrostatic motor 33 with - in the 0 ° position - the upper support surface 35a and the parallel lower support surface 35b. It is rotatably supported in the middle about the horizontal axis 36 arranged transversely to the conveying direction in the side walls 34 and its thickness is dimensioned such that the supporting surface 35a, 35b in the respective working position are aligned with the level of the stacking device and the exit of the molding machine. On the narrow longitudinal sides of the support plate 35, the locking holes 33, 39 and 40 are incorporated at opposite ends and on a web 37, into which the locking bolt 41 engages in the 0 °, 90 ° and 180 ° movement phases.

Under the support plate 35 (viewed in the 0 ° position) is the displacement device 42, consisting of the hydraulic or pneumatically operating stencil cylinder 43 and the thrust plate 44 aligned at right angles to the lower wing 35b.

Fig. 1 shows the tilting device in the working position, in which the bale 45 coming from the molding machine, in the two end faces of which a half shape is molded, are pushed together to form a bale strand 29 with vertical parting lines 46. They pass through the upper wing 35a of the tilting device 30.

In the manufacture and stacking of molded bales with a horizontal parting line, only two molded boxes (FIGS. 1 and 2) are used, and the molded halves 27a, 27b are removed. The operations are the same as listed above under 1. to 12. Only in operation 11, the two shaped bales 47 are not pushed as far as the bale strand, but rather onto the push plate 44 of the tilting device 30 pivoted by 90 ° and fixed here, the lower support surface 35b also serving as a stop (FIG. 4). Subsequently, the support plate 35 is rotated by a further 90 ° in the 13 ° rotation phase and locked in the locking hole 40. In this position, the displacement device 42 pushes the molded bale 47 with the width b turned through 90 ° against the molded bale strand 48, in which the parting lines 49 are then horizontal (FIG. 5).

Claims (7)

1. Molding machine for producing boxless molds with a mold box lying horizontally with its center line, which is open on both sides, the one opening of which can be closed by a horizontally acting press ram and the opposite opening can be closed by a swiveling press device, and in which a model half is located on at least one of the pressing surfaces facing one another is fastened, as well as with a stacking device onto which the finished pressed bale - after swiveling out the pressing device - is pushed horizontally through the molding box with the help of the ram, characterized in that at least one further molding box (4) open on both sides with the first molding box ( 3) is arranged in alignment between the press ram (12) and the pressing device (13), all mold boxes (3, 4) can be displaced along the center line of the mold box in a common horizontal guide (2) lying in the pressing and extending direction, and that between two neighboring ones n molding boxes (3, 4 ', 4', 4 ') each have a model support plate (21), the number of which is equal to the number of molding box joints, the cross section of which corresponds to the clear cross section of the molding boxes (3, 4), and which - in a manner known per se - can be extended and retracted when mold boxes (3, 4) are pulled apart. 2. Molding machine according to claim 1, characterized in that the model support plate (s) (21) is or are axially displaceable in the pressing and extending direction. 3. Molding machine according to claim 1 or 2, characterized in that the model support plate (s) (21) is or are designed as a pressing device (s). 4. Molding machine according to one of claims 1 to 3, characterized in that alternately different model halves (27 a / b, 28 a / b) are attached to the pressing tools (12, 14) and to the model supporting plates (21). 5. Molding machine according to one of claims 1 to 4, characterized in that the molding boxes (3, 4) can be coupled to the pressing tools (ram 12, pressing head 14). 6. Molding machine according to one of claims 1 to 5, characterized in that a tilting device (30) is arranged at its output (19), which optionally allows the pressed molded bales (45) to pass in an unchanged joint position, or with which the molded bales are pressed in pairs (47) can be tilted by 90 °. 7. Molding machine according to claim 6, characterized in that the tilting device (30) consists of a support plate (35) which is rotatably supported by 180 ° about its horizontal central axis (36), and which has an upper support surface (35a) and a lower one Has wing (35b), which are aligned in their operational positions with the level of the stacking device, and that a pushing device (42) acting in the pressing direction is attached to the lower wing (35b) with a thrust plate (44) oriented at right angles to it.

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