EP3682985A1 - Method for operating a light metal cold chamber pressure casting machine - Google Patents

Abstract

The light metal cold chamber die casting machine has a fixed platen (2) and two movable platen (6 and 7) arranged on opposite sides, whereby a casting mold (4, 5) is arranged between opposing platen (2 and 6) or (2 and 7) . Each movable platen (6, 7) is guided over two guide columns (8, 9; 10, 11) which pass through the fixed platen (2) and which are fixed to one movable platen (6, 7) and releasably attached to the other are (Figure 1).

Description

The invention relates to a method for operating a light metal cold chamber die casting machine and a light metal cold chamber die casting machine, in particular for carrying out this method.

In cold chamber die casting machines for die casting light metal, a large number of machine types are known, for example with a horizontally arranged or vertically arranged casting chamber, with clamping plates which can be moved horizontally or vertically to one another and the like.

The present invention is based on a cold chamber die casting machine, such as that used EP 3 053 672 A1 to the state of the art. In this machine, a central central platen is provided, on which fixed moldings are arranged on both sides. The associated movable molded parts are arranged on clamping plates, which can be moved on horizontal guide columns which are not shown in detail there.

Such guide columns are common in die casting machines and for example in EP 0 116 132 A1 shown. They serve on the one hand to guide the movable platen during its opening or closing movement and on the other hand to absorb the shooting forces, which ensure the cohesion of the molds during die casting. Particularly in the case of cold chamber die casting machines of the type mentioned at the beginning, in which two molding tools are filled at the same time and thus two movable clamping plates are arranged to the right and left of the fixed clamping plate, the shape size is limited by the distance between the guide columns, unless one or more guide columns are removed for tool change, i.e. for changing the molds. Such pulling of guide columns requires a considerable amount of free space next to the machine, in particular in the type mentioned at the beginning, in which the guide columns extend to both sides of the fixed platen. If such pillars, as is customary for shaping large workpieces, such as, for example, shock absorber supports for motor vehicles, are more than five meters long, then an equally long free space is required to remove these guide pillars, which is disadvantageous, quite apart from that associated with it time and technical effort.

In view of this prior art, the object of the invention is, on the one hand, to improve a method for operating such a light metal cold chamber die casting machine to avoid the aforementioned disadvantages, and on the other hand to design a light metal cold chamber die casting machine of the type mentioned at the outset in such a way that such an improved method for operating the Machine can be used and the aforementioned disadvantages of known machines can be avoided, at least reduced.

The procedural part of this object is achieved by a method with the features specified in claim 1. The device-related part of this object is achieved by a light metal cold chamber die casting machine with the features specified in claim 3. Advantageous embodiments of the invention are specified in the subclaims, the following description and the drawing.

The method according to the invention for operating a light metal cold chamber die casting machine, in which a fixed clamping plate and two clamping plates arranged on opposite sides are provided, each of which can be moved to at least one guide column for the purpose of opening and closing the casting tool arranged therebetween, and all of which when tools are closed Guide columns are fixed to the movable platen and penetrate the fixed platen, according to the invention, characterized in that to open the tools, the fixing of at least one guide column is released at one end and the guide column is removed from a movable platen, in such a way that with open molds, at least one guide column is fixed on each movable platen and passes through the fixed platen and that at least one guide column has one, preferably j loosened the movable platen and the space between the movable and the fixed platen is at least partially released.

The basic idea of the method according to the invention is therefore not only to remove at least one guide column for the tool change as is required in the prior art, but also to remove the guide columns at least partially when opening the tools in order to remove the space between the clamping plates for removing the workpiece and, if necessary also to enlarge the tool when changing and at the same time to reduce the required free space next to the machine. The guide column is fixed or released only on the movable platen, in such a way that at least one guide column remains to guide a movable platen and at least one guide column is removed from the area between a movable platen and the fixed platen.

Basically, at least two guide columns are required to carry out the method according to the invention. However, it is particularly advantageous to provide a casting machine with four guide columns, which are arranged in pairs opposite one another, in particular diametrically opposite one another, and coupled in pairs in relation to the longitudinal central axis of the tools lying in the direction of movement of the movable clamping plates. In this way, a reliable guidance on the one hand and an enlarged free space when the clamping plates are in the open position are ensured on the other hand. The method according to the invention can also be carried out with more than four guide columns. The guide columns are preferably arranged essentially horizontally, so that the direction of travel is also horizontal. In principle, however, the method according to the invention is not tied to a horizontal direction of travel.

The light metal cold chamber die casting machine according to the invention, which is provided in particular for carrying out the method according to the invention, has a casting chamber, a fixed platen and two movable platen arranged on opposite sides of the fixed platen. Opposing clamping plates are each designed to receive a casting mold and at least two guide columns are provided, which pass through the fixed clamping plate and of which at least one guide column is permanently fixed on one movable clamping plate and at least one other guide column on the other movable clamping plate.

According to the invention, the other end of at least one guide column fixed on a movable platen is releasably fixed on the other movable platen. The machine thus has at least two guide columns, one of which is permanently fixed to the one movable platen and the another is permanently fixed to the other movable platen, the other end of each of these guide pillars fixed to at least one movable platen being releasably attached to the other movable platen. The principle is that between a movable platen and the fixed platen, at least one guide column always remains connected for the purpose of guiding the movable platen when opening and closing, whereas the connection of the other end is released, so that an enlarged space for removing the Workpiece or for the exchange of the tool is created. As a result, the required lateral clearance, which is otherwise required to remove the guide columns, is significantly reduced at the same time.

Basically, in a deteriorated embodiment, the releasable arrangement of a guide column can only be provided on one side in a machine with a fixed and movable platen arranged on both sides of it, but it goes without saying that only the two-sided arrangement brings the full benefits. Then at least two guide columns are provided, of which one is fixed to a movable platen and passes through the fixed platen and the other end is releasably fixed to the other movable platen. The arrangement is such that when the connection between a movable platen and the guide column is released, the movable platen always remains connected to a guide column in order to ensure the guiding function.

However, it is particularly preferred if, according to an advantageous further development of the invention, the guide columns are diametrically opposite in pairs, with respect to the longitudinal central axis of the clamping plates lying in the direction of movement arranged horizontally and each pair is attached to a movable platen and releasably attached to the other. The arrangement of two pairs has proven to be particularly advantageous, which are preferably arranged so that their longitudinal axes are arranged on the corners of an imaginary square. However, three or four pairs of guide columns can also be provided. Combined solutions are also conceivable, in which individual guide columns are fixed on these clamping plates between a movable and the fixed platen and another is releasably fixed with one end on a movable platen.

In terms of manufacturing and assembly technology, it is particularly favorable if the movable platen plates are of identical, that is to say identical, design. This can easily be achieved with a symmetrical arrangement of four guide columns, each of which is arranged in pairs diametrically around the longitudinal central axis.

Defined in the sense of the present invention is to be understood as a permanent, fixed connection between the guide column and the movable platen, which is not released in normal production operation, that is to say during the injection molding of workpieces, or cannot reasonably be released for this purpose. Under releasably defined in the sense of the present invention is to be understood as such a definition that is so releasably defined that it is released in the production operation, that is to say in the normal injection molding process, after each workpiece casting and then fixed again, that is to say not such a connection, which, although Assembly and disassembly of the machine can be solved, but this cannot be solved during the manufacturing process, that is, between the individual "shots".

A positive locking device is advantageously provided on each guide column at one end and a tensioning device is provided at the other end, then both the guide function and the tensioning function can be implemented via the guide columns. The interlocking locking device is provided for realizing the releasably fixed end; locking devices of this type are state of the art in the field of die casting machines. As a clamping device, a hydraulic cylinder can typically be expediently provided, which is preferably arranged at the fixed end of the guide column between the guide column and the movable platen. It is expedient to design both the positive locking device and the tensioning device to be hydraulically actuated.

To move the movable platen, it is advantageous to provide separate linear drives which are expediently arranged between a movable platen and the fixed platen and arranged in parallel and close to the part on the guide column which is not removed when opening. Such linear drives can be driven electrically, pneumatically or preferably also hydraulically.

Such a linear drive is preferably formed by a pair of actuators, each actuator being arranged adjacent to the part of a guide column remaining between the fixed platen and the movable platen in order to limit as little as possible the space created when opening. The arrangement of a pair of actuators as a linear drive is particularly advantageous, since this reduces the risk of canting and a slim construction is possible.

In order to be effective both in the opening and in the closing direction, it is advantageous to use a double-acting hydraulic cylinder as the actuator.

In principle, the light metal cold chamber die casting machine according to the invention can be equipped with a horizontal or vertical casting chamber; the arrangement with a vertical casting chamber with sprue channels in the fixed platen is particularly advantageous.

According to an advantageous development of the invention, when using a vertical arrangement of the casting chamber, this can advantageously be arranged within the fixed platen.

In principle, it is neither necessary nor expedient for the guide columns to move completely out of the area between the fixed platen and the movable platen in the open position. In practice, it has proven itself if the detachable end of the guide column still protrudes in this area. Then, however, it is expedient to provide shields for protecting the free ends of the guide columns in the open position, so that these ends remain free of dust and sprue parts which can occur in this area due to flaking and the like when the mold is opened and the workpiece is removed. These shields are advantageously fastened to the fixed platen and each in the form of a column protection tube.

The cold chamber die casting machine according to the invention typically has two casting tools, each consisting of a stationary and a movable tool part. It is useful to arrange the fixed tool part on the fixed platen and the movable tool part on the movable platen. Depending on the design, one or more workpieces can then be manufactured simultaneously with each casting tool. Both casting tools are advantageously closed and opened at the same time.

Figur 1

in stark vereinfachte schematischer perspektivischer Darstel-lung eine Kaltkammerspritzgießmaschine gemäß der Erfin-dung in geöffneter Stellung und

Figur 2

die Maschine gemäß Figur 1 in Schließstellung.

The invention is explained below with reference to an embodiment shown in the drawing. Show it

Figure 1

in a greatly simplified schematic perspective representation, a cold chamber injection molding machine according to the invention in the open position and

Figure 2

the machine according to Figure 1 in the closed position.

The cold chamber die casting machine shown is a machine for producing die cast workpieces made of light metal. It has a machine bed 1 with which it is mounted standing on the floor. The machine bed carries all the essential components of the machine, of which only those essential for the present invention are described here. A fixed platen 2 is arranged centrally on the machine bed 1 and is part of a casting unit 3 arranged thereon. The casting unit 3 has a vertical casting chamber which is located within the fixed platen 2 and feeds the two molds 4 and 5, which are arranged between the fixed platen 2 and two movable platen 6 and 7 arranged on opposite sides of this platen 2. Between the fixed platen 2 and the movable platen 6 on the left in the figures, the left mold 4, consisting of a fixed mold half 4a and a movable mold half 4b, is arranged on the movable platen 6. Between the fixed platen 2 and the right in the figures movable platen 7, the right mold is arranged, consisting of a fixed tool half 5a arranged on the platen 2 and a movable tool half 5b attached to the platen 7.

The movable platen 6 and 7 are horizontally movable, and can from the in Figure 2 shown in the closed position in Figure 1 shown open position and vice versa, the closed position for die casting the workpiece and the open position for removing the workpiece and changing the tool is provided. Although the movable platen 6 and 7 are horizontally displaceably mounted on the machine bed 1, they are guided essentially by guide columns, namely that of the movable platen 6 by the guide columns 8 and 9 and that of the movable platen 7 by the guide columns 10 and 11 .

All four guide columns 6 to 9 are arranged parallel to one another horizontally and symmetrically about a longitudinal central axis 12 of the machine, which passes centrally through the molds 4 and 5 and the clamping plates 2, 6 and 7 in the direction of movement of the clamping plates 6 and 7. Relative to this central longitudinal axis 12, the guide columns 8 and 9 are arranged at 180 degrees to one another and the guide columns 10 and 11 are likewise offset from one another by 180 degrees. The guide columns 8 and 9 and 10 and 11 each form a pair of guide columns, the pairs of guide columns being arranged offset from one another by 90 degrees with respect to the central longitudinal axis 12, such that their longitudinal axes are in a plane transverse to the axis 12 on the imaginary corners of a square also lie in a circle.

All guide columns 8 to 11 are axially movable in the fixed platen 2. The guide columns 8 and 9 are with their left ends in the figures fixed to the left movable platen 6. The guide columns 10 and 11 are correspondingly fixed to the right movable platen 7. The arrangement is symmetrical, so that the clamping plates 6 and 7 are identical. In the Figure 1 visible right ends of the guide columns 8 and 9 and the left ends of the guide columns 10 and 11 are in the open position in the space between the clamping plates 2 and 7 or 2 and 6. These ends are cross-profiled, that is, have a plurality of in the axial direction circumferential grooves arranged one behind the other at a distance, which can be fixed in the closed position ( Figure 2 ) serve. To protect these form flow elements, protective tube sections are attached to the fixed platen 2 on each side, which surround the free ends of the guide columns 8 to 11 in the open position. These protective tubes are in Figure 1 not shown for overview purposes.

The ends of the guide columns 8 to 11 fixed in the clamping plates 6 and 7 are not fixed directly in the clamping plates 6 and 7, but are guided axially movably through them and received at the end in a hydraulic cylinder arrangement 13 which is firmly attached to the respective clamping plate 6 and 7, respectively and with their help in the closed position according to Figure 2 the required closing force is provided by pressurization.

In the Figure 1 Free ends of the guide columns 8 to 11 are passed through corresponding bores 14 in the movable mounting plates 6 and 7 in the closed position in order to be accommodated in hydraulic locking devices 15 arranged on the other side of these plates, which are likewise fixed to the movable mounting plates 6 and 7 and in the closed position fix the free end of a guide column 8, 9, 10 and 11 on the opposite platen 6, 7 detachably.

To the movable platen 6 and 7 along the guide columns 8 and 9 or 10 and 11 of the in Figure 1 shown open position in the closed position according to Figure 2 to move as well as in the opposite direction from the closed position to the open position parallel to the guide columns 8 to 11 radially outwardly arranged double-acting hydraulic cylinders 16 are provided, the piston rods of which are articulated on the fixed platen 2 and the cylinders of which are laterally connected to the movable platen 6 or are articulated on the movable platen 7. These hydraulic cylinders 16 are actuators for opening and closing the molds 4 and 5, they each form a pair of linear drives for the left platen 6 and the right platen 7. In the embodiment shown, the hydraulic cylinders 16 with their piston rods are on the fixed platen 2 articulated and the travel cylinders to the movable platen 6 and 7. This arrangement has the advantage that the hydraulic connections arranged on the drive cylinder side are arranged away from the fixed platen 2, which can be particularly advantageous for reasons of space. However, the hydraulic cylinders 16 can also be arranged upside down, ie articulated with the travel cylinders on the fixed platen 2 and articulated with the piston rods on the movable platen 6 and 7. Such an arrangement has the advantage that the piston rods are arranged outside the area that are particularly exposed when the tool is opened.

In the Figure 1 The open position of the machine shown can also be used to change the tool, that is to say to change the molds 4 and 5, and there are large free spaces due to the guide column sections drawn in pairs, which facilitate tool change.

However, this position serves according to Figure 1 not only for tool changes, but also for workpiece removal. The workpieces are in Figure 1 marked with 17. This arrangement is particularly advantageous for fully automated or partially automated operation, since large free spaces are formed here due to the partially drawn guide columns, which in particular facilitate robotically controlled interventions.

To die-cast the workpieces, the movable platen 6 and 7 are removed from the in FIG Figure 1 shown open position in the Figure 2 Move the closed position shown, in which the mold halves 4a and 4b and 5a and 5b lie close together. Then the free ends of the guide columns 8 to 11 with their positive locking elements (grooves) are passed through the bores 13 of the clamping plates 6 and 7 and fixed by means of the hydraulic locking devices 15. The closing force required for the pressure casting process is then applied by means of the hydraulic cylinders 14, after which liquid light metal is pressed into the casting molds 4 and 5 by means of the casting unit 3 through the sprue channels located in the fixed platen 2. After the material has cooled, the hydraulic cylinders 14 are relieved of pressure, the locking devices 15 are opened and, by means of the hydraulic cylinders 16, the clamping plates 6 and 7 with the movable tool halves 4b and 5b thereon are returned to the in FIG Figure 1 driven open position shown, in which the workpieces are removed, after which the machine is ready for another die casting process. The above-described method is continued with a comparatively short cycle time, two molds 4 and 5 being filled and two workpieces 17 being formed accordingly.

Reference list

1

Machine bed

2nd

fixed platen

3rd

Casting unit

4th

Left mold

4a

Fixed tool half on the left

4b

Movable tool half on the left

5

Right mold

5a

Fixed tool half on the right

5b

Movable tool half on the right

6

Movable platen on the left

7

Movable clamping plate on the right

8th

Guide column for movable clamping plate on the left

9

Guide column for movable clamping plate on the left

10th

Guide column for movable clamping plate on the right

11

Guide column for movable clamping plate on the right

12th

Longitudinal central axis

13

Holes in the movable platen

14

Hydraulic cylinder

15

Hydraulic locking device

16

Double-acting hydraulic cylinder

17th

Workpieces

Claims (15)

Method for operating a light metal cold chamber die casting machine, in which a fixed platen (2) and two movable platen (6, 7) arranged on opposite sides are provided, each on at least one guide column (8, 9, 10, 11) for the purpose of opening and closing the casting tool (4, 5) arranged therebetween can be moved, with closed tools (4, 5) all guide columns (8-11) being fixed to the movable platen (6, 7) and passing through the fixed platen (2), characterized in that for opening the tools (4, 5) the fixing of at least one guide column (8, 9, 10, 11) is released at one end and the guide column (8, 9, 10, 11) is moved by a movable platen (6, 7) is removed in such a way that when the casting tools (4, 5) are open, at least one guide column (8, 9, 10, 11) is fixed on each movable platen (6, 7) and the fixed platen (2) is fixed and that at least one guide column (8, 9, 10, 11) is detached from one, preferably each movable platen (6, 7) and the space between the movable and the fixed platen (2) is at least partially released. Method according to Claim 1, characterized in that the guide columns (8, 9, 10, 11) are coupled in pairs, preferably diametrically opposite, in relation to the longitudinal center axis (12) of the tools (4, 5) lying in the direction of movement. Light metal cold chamber die casting machine, in particular for carrying out the method according to one of the preceding claims, with a casting chamber, with a fixed platen (2) and with two movable clamping plates (6, 7) arranged on opposite sides of the fixed clamping plate (2), opposite clamping plates 2, 6; 2, 7) are each designed to receive a casting mold (4, 5), with at least two guide columns (8-11) which pass through the fixed platen (2) and at least one guide column (8, 9, 10, 11) on one movable platen (6, 7) and at least one other guide column (8, 9, 10, 11) on the other movable platen (6, 7), characterized in that the other end of at least one guide column (8, 9, 10, 11) is releasably attached to a movable platen (6, 7). Light metal cold chamber die casting machine according to claim 3, characterized in that the guide columns (8-11) are arranged in pairs opposite one another, preferably diametrically opposite, in relation to the longitudinal central axis (12) of the clamping plates (6, 7) and each pair is arranged on a movable clamping plate 6, 7) and is releasably attached to the other. Light metal cold chamber die casting machine according to claim 4, characterized in that preferably two or three or four pairs of guide columns (8-11) are provided. Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that the two movable clamping plates (6, 7) are of identical design. Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that on each guide column (8-11) at one end a positive locking device (15) and at the other end a tensioning device (14), which are preferably operated hydraulically. Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that a linear drive (16) is preferably provided parallel to a guide column (8, 9, 10, 11) between the fixed platen (2) and the movable platen (6, 7). Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that the linear drive has a pair of actuators, each actuator (16) being arranged adjacent to the guide column (8-11) remaining between the fixed platen (2) and the movable platen (6, 7) is. Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that an actuator (16) is formed by a double-acting hydraulic cylinder (16). Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that the casting chamber is arranged vertically and is channel-connected to sprue channels in the fixed platen (2). Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that the casting chamber is arranged vertically and within the fixed platen (2). Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that shields are provided to protect the free ends of the guide columns in the open position. Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that each casting tool (4, 5) has a fixed tool part (4a, 5a) arranged on the fixed platen (2) and a movable tool part arranged on the movable platen (6, 7) (4b, 5b). Light metal cold chamber die casting machine according to one of the preceding claims, characterized in that the shield has a column protection tube attached to the fixed platen (2).

Images