EP0047507B1 - Moulding machine for making flaskless moulds - Google Patents

Description

The invention relates to a molding machine according to the preamble of claim 1. 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 produced when pushed onto the stacking device (see e.g. DE-PS 1211 760).

This process has significant advantages over that in which the pressing forces act vertically on 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, it is known that the hardened molds are smashed and the castings are probed. The mold sand 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 main advantage of the molding machine with horizontal production direction described at the outset is that it only requires half the molding sand compared to machines with a vertical production direction.

Various proposals have already been made to increase the performance of molding machines with a horizontal pressing direction. For example, in the extrusion molding system according to DE-PS 24 05 371, the molding box support is designed as a rotary table with a step drive, and there are a plurality of molding 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 press station requires its own press device and each ejection station its own ejection 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 on. 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 therefore a higher risk of rejects.

In the molding machine according to DE-AS 25 28 645 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. Blowing seals are used to seal the joints between the abutment plate and the mold cavities in the press position. After the pressing process, the slides are pushed into the ejection positions, and the two shaped bales are each pushed onto a tilting device and tilted here by 90 ° about a horizontal axis transverse 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. 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. 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 there is space for a pressing device acting in both horizontal directions, so that the molding sand is compacted from both sides. This creates four bale strands in pairs and in parallel. For stacking molded bales with a horizontal parting line, two bale halves with a vertical parting line are also added outside the machine, rotated by 90 ° using a tilting device and pushed onto a transport system transversely to the pressing direction. Because of the inevitable running play of the two double mold boxes and the large displacement of the mold bales, a correspondingly large offset is also inevitable with this machine.

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

Molding machines with retractable and extendable model support plates are known from DE-C-23 03 561.

The present invention has for its object, while avoiding the shortcomings of the machines described above, the performance like to increase the shape of molding machines with a horizontal pressing direction and to design them in such a way that bale strands with a horizontal parting line between the halves of the bale can also be produced. 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, for example, to brake disks, clutch disks, and the like, which are 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.

To solve this problem, the characterizing features of claim 1 are proposed.

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 guaranteed. With the combination according to the invention of mold boxes which are axially displaceable and retractable and extendable model support plates, this machine is excellently 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 very 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 either allows the pressed molded bales to pass through in an unchanged joint position, or with which molded molded bales are tilted 90 °.

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 was to be produced. For a large foundry, this should hardly matter. However, as before, one can also make do with a pair of model halves 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.
• Fig. 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 through 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 plan 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 punch 12 of which has penetrated into the molding box 3. At the opposite end there is the pressing device 13 with a box-shaped pressing head 14 which can be expanded by internal pressure and which is fastened to the shaft 17 of the servomotor 18 by means of a swivel arm 16 and can be 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 molded 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 molding boxes in the direction of the molding 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 boxes 3, 4 can be coupled to the pressing die 12 and the pressing 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 Formkastens 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 Modelltragplatte,
• 6. Ankuppeln und Auseinanderziehen der beiden Formkästen 3, 4,
• 7. Ausfahren der Modelltragplatte 21,
• 8. gegebenenfalls Kerne einlegen,
• 9. Abkuppeln des Formkastens 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
• 12. Rückführen der am Pressstempel 12 angekuppelten Formkästen 3, 4 in ihre Ausgangspositionen, wobei der Formkasten 4 - nach Erreichen seiner Ausgangsposition - vom Pressstempel 12 abgekuppelt wird.

In the starting position, the two mold boxes 3, 4 have moved apart, the model support plate 21 is located outside the machine. The individual work stages run as follows, the respective end positions being 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. Close 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, the pressing device and the model support plate,
• 6. Coupling and pulling 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 out the press head 14,
• 10. Move the mold 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
• 12. Returning the molded boxes 3, 4 coupled to the press die 12 to their starting positions, the molded box 4 being uncoupled from the press die 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 21 ', 21" 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. Theoretically, 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 the 0 ° position of 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 32 and the exit of the molding machine . On the narrow longitudinal sides of the support plate 35, the locking holes 38, 39 and 40 are incorporated at opposite ends and on a web 37, into which the locking bolt 41 engages in the movement phases 0 °, 90 ° and 180 °.

Under the support plate 35 '(viewed in the 0 ° position), the displacement device 42, consisting of the hydraulically or pneumatically operating actuating cylinder 43 and the thrust plate 44 oriented at right angles to the lower support surface 35b, is attached.

1, 4, 6 show the tilting device in the working position, in which the bale 45 coming from the molding machine, in the two end faces of which half a 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 are the two shaped bales 47 not pushed as far as the bale strand, but onto the push plate 44 of the tilting device 30 pivoted by 90 ° and fixed here, the lower wing 35b also serving as a stop (FIG. 4) rotated by a further 90 ° into the 130 ° 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. A molding machine for producing flaskless molds (29) having a molding box (3) located horizontally with respect to its center line and open on both sides, one opening of which is closable by a horizontally operating die (12) and the opposite opening is closable by an outwardly pivotable pressing device (13), and in which one half of a pattern (27 a, 27 b) is secured to at least one of the pressure faces oriented toward one another, further having a stacking device (32) onto which the completed, pressed mold body, after the outward pivoting of the pressing device (13), is pressed horizontally all the way through the molding box with the aid of the die (12), characterized in that at least one further molding box open on both sides is disposed in alignment with the first molding box between the die and the pressing device, all the molding boxes are displaceable along the central line of the molding boxes in a common, horizontal guideway, located in the direction of pressure and discharge, and that between each two adjacent molding boxes a match plate is provided, the number of which is equal to the number of the molding box seams, whose cross section corresponds to the inside cross section of the molding of the molding boxes, and which is or are drivable in and out in a manner known per se when each match plate being constructed and arranged to be extracted from between the molding boxes when taken apart.

2. A molding machine according to claim 1, characterized in that the match plate(s) (21 ) being also designed to be coaxially movable in the pressing and discharching direction.

3. A machine as defined by claim 1 characterized in that each pattern carrier plate (or plates (21 ) is (or are) embodied as a pressing device (or as pressing devices).

4. A machine as defined by claim 1 characterized in that different pattern halves (27a/b, 28a/b) are attachable in alternation to the pressing tools (12,14) and to the match plates (21).

5. A machine as defined by claim 1, characterized in that means are provided for coupling the molding boxes (3, 4) to the pressing tools (plate 12, pressing davice 13).

6. A machine as defined by claim 1, characterized in that disposed at its outlet (19) is a tilting device (30), which selectively permits the pressed mold bodies (45) to continue past it with its seams in an unchanged position, or with which the mold bodies (47) pressed in pairs can be tilted by 90°.

7. A machine as defined by claim 6, characterized in that the tilting device comprises a carrier plate (35), which is supported such that it is rotatable by 180° about its horizontal center axis (36) and which has an upper carrier face (35a) and a lower carrier face, which in their operating positions are in alignment with the level of the stacking device, and that a displacement device (42) acting in the pressure direction is secured to the lower carrier face (35b) with a thrust plate (44) directed at a right angle to the displacement divice.

Images