EP3914407B1 - Method for operating a casting machine and casting machine - Google Patents

Description

The invention relates to a method for operating a casting machine and a casting machine, in particular for carrying out this method. Casting machine within the meaning of the present invention can be a die casting machine, in particular a light metal cold chamber die casting machine or a light metal hot chamber die casting machine, or an injection molding machine, e.g. for plastic.

In the case of 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 in relation to one another, and the like.

The present invention is based on a cold-chamber die-casting machine, as is the case, for example EP 3 053 672 A1 belongs to the state of the art. In this machine, a middle, central clamping plate is provided, on which fixed mold parts are arranged on both sides. The associated movable mold 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 are used, for example, in EP 0 116 132 A1 shown. On the one hand, they serve to guide the moving platens during their opening and closing movements and, on the other hand, to absorb the closing forces that hold the casting tools together during the casting process ensure die casting. Particularly in the case of cold chamber die casting machines of the type mentioned at the beginning, in which two casting molds are filled at the same time and therefore two movable platens are arranged to the right and left of the fixed platen, the size of the mold and thus the size of the mold is limited by the distance between the guide columns, unless the Tool change, i.e. one or more guide columns are removed to change the casting tools. Such a pulling of guide columns requires a considerable amount of free space next to the machine, particularly in the case of the design mentioned at the outset, in which the guide columns extend on both sides of the stationary platen. If such columns, as is usual for molding large workpieces such as strut supports for motor vehicles, are more than five meters long, then an equally long clearance is required to remove these guide columns, which is disadvantageous, not to mention the associated one time and technical effort.

A similar caster is off JP 2015140001A known. There, the guide columns are fixed to one of the movable platens, being movably fixed in the fixed platen and movably but not releasably fixed in the other movable platen. To release, pull the guide pillars fully.

Also with the off JP S62 132621 A known casting machine, the guide columns are arranged continuously through the stationary and the movable platens, so that they are connected to the platens both when the molds are closed and when they are open.

Against this prior art, the invention according to the application is based on the object of improving a method for operating such a casting machine in order to avoid the aforementioned disadvantages, and designing a casting machine of the type mentioned at the outset in such a way that such an improved method can be used for operation the machine can be used and the aforementioned disadvantages of known machines can be avoided, at least reduced.

The procedural part of this task is solved by a method with the features specified in claim 1 . The device part of this problem is solved by a casting machine with the features specified in claim 3. Advantageous configurations of the invention are indicated in the dependent claims, the following description and the drawing.

The method according to the invention for operating a casting machine, in particular a light metal cold chamber or hot chamber die casting machine or an injection molding machine, in which a fixed platen and two movable platens arranged on opposite sides are provided, each on at least one guide column for the purpose of opening and closing the intermediate arranged casting tool can be moved and in which, when the tools are closed, all the guide columns are fixed to the movable platens and pass through the fixed platen, is characterized according to the invention in that, in order to open the tools, the fixing of at least two guide columns is released at one end and the guide columns of removed from a movable platen in such a way that, when the molds are open, at least one guide column is fixed to each movable platen and penetrates the fixed platen, and that at least one guide column is detached from each movable platen and fills the space between the movable and the fixed platen is arranged at least partially releasing.

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

In principle, 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, relative to the longitudinal center axis of the tools in the direction of movement of the movable platens and are movement-coupled in pairs. This ensures reliable guidance on the one hand and increased free space when the clamping plates are in the open position on the other. 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 casting machine according to the invention, which is provided for carrying out the method according to the invention, has a fixed platen and two movable platens arranged on opposite sides of the fixed platen. Opposite clamping plates are each designed to accommodate 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 to one movable clamping plate and at least one other guiding column to the other movable clamping plate.

It goes without saying that a casting machine within the meaning of the invention can be a light metal die casting machine or, for example, a plastic injection molding machine. In the first case, it can be a cold chamber or a hot chamber die casting machine, which has a casting chamber or a holding furnace. In the case of an injection molding machine, at least one extruder is expediently integrated into the machine.

According to the invention, the other end of a tie bar fixed to one movable platen is detachably fixed to the other movable platen. The machine thus has at least two guide columns, one of which is permanently fixed to one movable platen and the other is permanently fixed to the other movable platen, the other end of each of these guide columns fixed to at least one movable platen being attached to the other movable platen Clamping plate is releasably attached. The principle is such that between a movable platen and the fixed platen there is always at least one guide column connected for the purpose of guiding the movable platen when opening and closing, whereas the connection of the other end is released, so that there is more free space for removing the Workpiece or also to replace the mold so the tool is created. At the same time, this significantly reduces the required lateral clearance, which is otherwise required to remove the guide columns.

In principle, in a deteriorated embodiment in a machine with a fixed and movable platens arranged on both sides thereof, the detachable arrangement of a guide column could only be provided on one side, but it goes without saying that only the two-sided arrangement according to the invention achieves the full advantages brings with it. According to the invention, at least two guide columns are provided, one of which is fixed to a movable platen and penetrates the fixed platen and the other end is detachably 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 development of the invention, the guide columns are arranged in pairs, preferably diametrically opposite one another, relative to the longitudinal center axis of the clamping plates in the direction of movement, and each pair is fixed to one movable clamping plate and releasably fixed to the other. The arrangement of two pairs has proven to be particularly advantageous, which are preferably arranged in such a way 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 between a movable and the fixed platen on these platens and another one is detachably fixed with one end on a movable platen.

It is particularly favorable in terms of production and assembly if the movable platens are the same, that is to say identical in design. This can easily be implemented with a symmetrical arrangement of four guide columns, which are each arranged in pairs diametrically around the longitudinal central axis.

For the purposes of the present invention, fixed means a permanently fixed connection between the guide column and the movable platen, which is not loosened during normal production operation, ie during the successive casting of workpieces, or cannot reasonably be loosened for this purpose. For the purposes of the present invention, releasably fixed is to be understood as meaning a fixing that is releasably fixed in such a way that it is released during production, i.e. in the normal casting process, after each workpiece casting and then fixed again, i.e. not such a connection which, although Assembly and disassembly of the machine can be solved, but during the manufacture of molded parts, that is between the individual "shots" is not solved.

Advantageously, each guide column has a positive-locking locking device at one end and a clamping device at the other end, so that both the guiding function and the clamping function can be implemented via the guide columns. The interlocking locking device is provided to realize the releasably fixed end; such locking devices are state of the art in the field of die casting machines. A hydraulic cylinder, expediently a ring cylinder, can typically be provided as the clamping device, which is preferably arranged at the fixed end of the guide column between the guide column and the movable clamping plate. It is expedient here to design both the positive locking device and the tensioning device to be hydraulically actuated.

To move the movable platens, it is advantageous to provide separate linear drives which are conveniently arranged between a movable platen and the fixed platen and parallel and close to the part on the Guide column is arranged, 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 restrict the free space created during opening as little as possible. The arrangement of an actuator pair as a linear drive is particularly advantageous, since this reduces the risk of tilting and a slim design 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.

The casting machine according to the invention preferably has two casting tools, each consisting of a fixed and a movable tool part. It is expedient to arrange the stationary tool part on the stationary 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.

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

If the casting machine according to the invention is a light metal die-casting machine, it advantageously has a casting chamber which is arranged vertically and which is channel-connected to sprue channels in the fixed platen.

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

If the light metal die casting machine is a light metal hot chamber die casting machine, then it may be advantageous to locate the machine's holding furnace within the fixed platen or in an area above it.

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 useful if the detachable end of the guide column still protrudes into this area. Then, however, it is useful to provide shields to protect the free ends of the guide columns in the open position, so that these ends remain free of dust and sprue parts that can occur in this area due to spalling and the like when opening the mold and removing the workpiece. These shields are advantageously fastened to the fixed platen and are each designed in the form of a column protection tube.

Figur 1

in stark vereinfachte schematischer perspektivischer Darstellung eine Kaltkammerspritzgießmaschine gemäß der Erfindung in geöffneter Stellung,

Figur 2

die Maschine gemäß Figur 1 in Schließstellung,

Figur 3

eine Leichtmetallwarmkammerdruckgießmaschine in Darstellung gemäß Figur 1,

Figur 4

die Maschine gemäß Figur 3 in Seitenansicht mit feststehender Aufspannplatte im Längsschnitt

Figur 5

eine Kunststoffspritzgießmaschine in Darstellung gemäß Figur 1,

Figur 6

die Maschine gemäß Figur 5 in Draufsicht und

Figur 7

eine andere Ausführung einer Kunststoffspritzgießmaschine in Darstellung gemäß Figur 6.

The invention is explained in more detail below with reference to exemplary embodiments illustrated in the drawing. Show it

figure 1

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

figure 2

the machine according to figure 1 in closed position,

figure 3

a light metal hot chamber die casting machine as shown in FIG figure 1 ,

figure 4

the machine according to figure 3 in side view with fixed clamping plate in longitudinal section

figure 5

a plastic injection molding machine as shown in FIG figure 1 ,

figure 6

the machine according to figure 5 in top view and

figure 7

another embodiment of a plastic injection molding machine as shown in FIG figure 6 .

When using the figures 1 and 2 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 on the floor. The machine bed carries all the essential components of the machine, of which only those essential to the present invention are described here. A stationary platen 2 is arranged centrally on the machine bed 1 and is part of a casting unit 3 arranged thereon. The pouring unit 3 comprises a vertical pouring chamber located within the fixed platen 2 and feeding two molds 4 and 5 located between the fixed platen 2 and two movable platens 6 and 7 arranged on opposite sides of this platen 2 are arranged. Between the stationary platen 2 and the movable platen 6 on the left in the figures, the left casting mold 4 consisting of a stationary mold half 4a and a movable mold half 4b is arranged on the movable mold plate 6 . Between the fixed platen 2 and the movable platen 7 on the right in the figures, the right-hand 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 platens 6 and 7 can be moved horizontally and can be moved from the position shown in figure 2 shown closed position to the in figure 1 be moved to the open position shown and vice versa, the closed position being provided for die-casting the workpiece and the open position for removing the workpiece and changing the tool. Although the movable platens 6 and 7 are mounted on the machine bed 1 so that they can be displaced horizontally, they are essentially guided 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 platens 2, 6 and 7 in the direction of movement of the platens 6 and 7. In relation to this central longitudinal axis 12, the guide columns 8 and 9 are offset by 180 degrees to one another and the guide columns 10 and 11 are also offset by 180 degrees to one another. The guide columns 8 and 9 as well as 10 and 11 each form a guide column pair, the pairs of guide columns being offset from one another by 90 degrees relative to the central longitudinal axis 12 such that their longitudinal axes lie in a plane transverse to the axis 12 at the imaginary corners of a square or a circle.

All guide columns 8 to 11 are guided in the fixed platen 2 so that they can move axially. The guide columns 8 and 9 are fixed to the left-hand movable platen 6 with their ends on the left in the figures. The tie bars 10 and 11 are respectively fixed to the movable platen 7 on the right. The arrangement is symmetrical, so that the clamping plates 6 and 7 are of identical design. In the figure 1 Visible right-hand ends of the guide columns 8 and 9 and the left-hand ends of the guide columns 10 and 11 are in the open position in the free space between the clamping plates 2 and 7 or 2 and 6. These ends are cross-profiled, i.e. point a large number of in the axial direction circumferential grooves arranged one behind the other at a distance, which are used for fluid fixing in the closed position ( figure 2 ) serve. To protect these form-flow elements, protective tube sections are fastened to each side of the fixed platen 2, 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 clarity.

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 through them so that they can move axially and are received at the ends in a hydraulic cylinder arrangement 13, which is firmly attached to the respective clamping plate 6 or 7 is and with the help of which in accordance with the closed position figure 2 the required closing force is provided by applying pressure.

In the figure 1 free ends of the guide columns 8 to 11 are passed in the closed position through corresponding bores 14 in the movable platens 6 and 7 in order to be received in hydraulic locking devices 15 arranged beyond these plates, which are also fixedly arranged on the movable platens 6 and 7 and in the closed position fix the respective free end of a guide column 8, 9, 10 and 11 to the opposite clamping plate 6, 7 releasably.

In order to move the movable platens 6 and 7 along the guide columns 8 and 9 or 10 and 11 from the in figure 1 shown open position in accordance with the closed position figure 2 to move and in the opposite direction from the closed position to the open position, double-acting hydraulic cylinders 16 are provided parallel to the guide columns 8 to 11 and offset radially outwards, the piston rods of which are articulated on the fixed platen 2 and the cylinders of which are attached laterally to the movable platen 6 or are hinged to the movable platen 7 . These hydraulic cylinders 16 are actuators to open and close the casting molds 4 and 5, they each form a linear drive in pairs for the left-hand clamping plate 6 and the right-hand clamping plate 7. In the illustrated embodiment, the hydraulic cylinders 16 with their piston rods are on the fixed clamping plate 2 articulated and the driving cylinders on the movable platens 6 and 7. This arrangement has the advantage that the hydraulic connections arranged on the driving 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 in reverse, ie articulated with the driving cylinders on the stationary platen 2 and articulated with the piston rods on the movable platens 6 and 7 . Such an arrangement has the advantage that the piston rods are arranged outside the area that is particularly exposed when the tool is opened.

In the figure 1 The illustrated open position of the machine can also be used to change tools, ie to change the casting molds 4 and 5. This results in large free spaces due to the guide column sections drawn in pairs, which facilitate the tool change.

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

For die casting of the workpieces, the movable platens 6 and 7 are moved by means of the hydraulic cylinders 16 from the figure 1 illustrated open position to the in figure 2 process shown closed position, in which the mold halves 4a and 4b and 5a and 5b lie tightly against each other. Then the free ends of the guide columns 8 to 11 with their form-fitting 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 die-casting process is then applied by means of the hydraulic cylinder 14, after which liquid light metal is pressed into the molds 4 and 5 through the sprue channels located in the fixed platen 2 by means of the casting unit 3. After the material has cooled, the hydraulic cylinders 14 are depressurized, the locking devices 15 are opened and, by means of the hydraulic cylinders 16, the clamping plates 6 and 7 with the thereon located movable tool halves 4b and 5b back into the in figure 1 driven open position shown, in which the workpieces are removed, after which the machine is ready for a renewed die casting process. The method described above is continued with a comparatively short cycle time, with two casting molds 4 and 5 being filled and correspondingly two workpieces 17 being formed.

The basic machine structure described above using a light metal cold chamber die casting machine and the operation of this machine for the production of workpieces and tool changes can be used in the same way on light metal hot chamber die casting machines or injection molding machines such as those used for processing plastic. Based on Figures 3 and 4 shows a light metal die casting machine that works according to the hot chamber principle. There, instead of the casting chamber, which is in the machine in the figures 1 and 2 Is used, a holding furnace 18 is provided, which is integrated within the fixed platen 2 and the channels 19 with the Figures 3 and 4 not shown molds is connected.

Based on figures 5 and 6 a plastic injection molding machine constructed according to the same principle is shown, which has two extruders 20 via which the molding material is supplied to the tools. How based on figures 5 and 6 can be seen, the liquid casting material is not fed through the central fixed platen 2 but directly to the tools 4, 5.

In the case of figure 7 Plastic injection molding machine shown, which is also constructed according to the principle described above, only one extruder 20 is provided, which next to the fixed Clamping plate 2 is arranged essentially transversely to the machine bed 1 and which conveys the liquid material via channels in the stationary clamping plate 2 to the two tools (those in the figure 7 are not shown), are supplied.

Reference List

1

machine bed

2

fixed platen

3

casting unit

4

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 clamping plate on the left

7

Movable clamping plate on the right

8th

Guide column for moveable clamping plate on the left

9

Guide column for moveable clamping plate on the left

10

Guide column for movable clamping plate on the right

11

Guide column for movable clamping plate on the right

12

longitudinal central axis

13

Holes in the moveable platens

14

hydraulic cylinder

15

Hydraulic locking device

16

Double-acting hydraulic cylinder

17

workpieces

18

holding furnace

19

channels

20

extruder

Claims (17)

1. A method for operating a die casting or injection moulding machine comprising a stationary platen (2) and two movable platens (6, 7), which are arranged at opposite sides of the stationary platen and respectively can be displaced on at least one guide column (8, 9, 10, 11) for the purpose of opening and closing the casting mould (4, 5) arranged in between, wherein all guide columns (8-11) are fixed on the movable platens (6, 7) and pass through the stationary platen (2) when the moulds (4, 5) are closed, characterized in that, in order to open the moulds (4, 5), the fixation of at least two guide columns (8, 9, 10, 11) is separated on one end and the guide columns (8, 9, 10, 11) are removed from a movable platen (6, 7) in such a way that, when the casting moulds (4, 5) are open, at least one guide column (8, 9, 10, 11) is fixed on each movable platen (6, 7) and passes through the stationary platen (2) and that at least one guide column (8, 9, 10, 11) is separated from each movable platen (6, 7) and arranged so as to at least partially vacate the space between the movable platens and the stationary platen (2), wherein the term fixed refers to a permanently fixed connection between guide column and movable platen, which is not separated in the normal production mode during successive casting of workpieces, and wherein the term separably fixed refers to a fixation that is separably fixed in such a way that it is separated after each workpiece casting and then once again fixed in the production mode, i.e. in the normal casting process.
2. The method according to claim 1, characterized in that the guide columns (8, 9, 10, 11) are motion-coupled in opposing pairs, preferably diametrically opposing pairs, referred to the longitudinal center axis (12) of the moulds (4, 5) extending in the moving direction.
3. A casting machine for carrying out the method according to one of the preceding claims, comprising a stationary platen (2) and two movable platens (6, 7), which are arranged at opposite sides of the stationary platen (2), wherein opposing platens (2, 6; 2, 7) respectively are designed for receiving a casting mould (4, 5), wherein said casting machine furthermore comprises at least two guide columns (8-11) that pass through the stationary platen (2), and wherein at least one of said guide columns (8, 9, 10, 11) is fixed on one movable platen (6, 7) and at least one other guide column (8, 9, 10, 11) is fixed on the other movable platen (6, 7), characterized in that the other ends of the guide columns (8, 9, 10, 11) are separably fixed on a movable platen (6, 7), wherein the term fixed refers to a permanently fixed connection between guide column and movable platen, which is not separated in the normal production mode during successive casting of workpieces, and wherein the term separably fixed refers to a fixation that is separably fixed in such a way that it is separated after each workpiece casting and then once again fixed in the production mode, i.e. in the normal casting process.
4. The casting machine according to claim 3, characterized in that the guide columns (8-11) are arranged in opposing pairs, preferably diametrically opposed pairs, referred to the longitudinal center axis (12) of the platens (6, 7) extending in the moving direction, and in that each pair is fixed on one movable platen (6, 7) and separably fixed on the other movable platen.
5. The casting machine according to claim 4, characterized in that two or three or four pairs of guide columns (8-11) preferably are provided.
6. The casting machine according to one of the preceding claims, characterized in that the two movable platens (6, 7) are designed identically.
7. The casting machine according to one of the preceding claims, characterized in that each guide column (8-11) has on one end a positive locking device (15) and on the other end a clamping device (14), which preferably are actuated hydraulically.
8. The casting machine according to one of the preceding claims, characterized in that a linear drive (16) preferably is provided parallel to a guide column (8, 9, 10, 11) between the stationary platen (2) and the movable platen (6, 7).
9. The casting machine according to one of the preceding claims, characterized in that the linear drive has an actuator pair, wherein each actuator (16) is arranged adjacent to the guide column (8-11) remaining between the stationary platen (2) and the movable platen (6, 7).
10. The casting machine according to one of the preceding claims, characterized in that an actuator (16) is formed by a double-action hydraulic cylinder (16).
11. The casting machine according to one of the preceding claims, characterized in that each casting mould (4, 5) comprises a stationary mould part (4a, 5a) arranged on the stationary platen (2) and a movable mould part (4b, 5b) arranged on the movable platen (6, 7).
12. The casting machine according to one of the preceding claims, characterized in that the casting machine is a hot-chamber or cold-chamber die casting machine with a casting chamber, which is arranged vertically and channel-connected to feed channels in the stationary platen (2).
13. The die casting machine according to claim 12, characterized in that the casting chamber is arranged within the stationary platen (2).
14. The die casting machine according to one of the preceding claims, characterized in that shields are provided for protecting the free ends of the guide columns in the open position.
15. The die casting machine according to claim 14, characterized in that the shield comprises a column protection tube, which is fastened on the stationary platen (2).
16. The die casting machine according to one of the preceding claims, characterized in that the die casting machine is a hot-chamber die casting machine and the holding furnace is arranged within the stationary platen (2).
17. The casting machine according to one of claims 3 to 10, characterized in that the casting machine is an injection moulding machine with an extruder, which is arranged adjacent to the stationary platen (2) transverse to the moving direction.

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