INJECTION MOULD

Abstract

Injection mould for producing mouldings having a cavity plate with cavities and a core plate with cores. The cavity plate and the core plate are movable between a closed position, in which each core is respectively arranged in a cavity, and an open position, in which no core is arranged within a cavity. Each moulding space is assigned a neck-ring pair with two neck rings, and the neck-ring pair is arranged on the core plate and is movable between a holding position, in which neck rings of the neck-ring pair are in contact, and a releasing position, in which neck rings of the neck-ring pair are not in contact. To provide an injection mould with which mouldings can be produced and provided for further processing as efficiently as possible, the cores and the cavities are arranged on a curved path.

Claims

1. An injection mould for producing mouldings having a cavity plate which has cavities, the inner contour of which corresponds at least to a portion of the outer contours of the mouldings to be produced, and a core plate which has cores, the outer contour of which corresponds at least to a portion of the inner contours of the mouldings to be produced, wherein the cavity plate and the core plate are movable back and forth relative to one another between a closed position, in which each core is respectively arranged in a cavity, and an open position, in which no core is arranged within a cavity, wherein, in the closed position, a moulding space for receiving a plasticized melt is formed by each cavity and the core arranged therein, wherein each moulding space is assigned a neck-ring pair made up of two neck rings, wherein the inner contour of the neck-ring pair corresponds to a portion of the outer contour of the moulding to be produced, wherein the neck-ring pair is arranged on the core plate and can be moved back and forth between a holding position, in which the two neck rings of the neck-ring pair are in contact with one another, and a releasing position, in which the two neck rings of the neck-ring pair are not in contact with one another, and wherein the cores and the cavities are arranged on a curved path.

2. The injection mould according to claim 1, wherein the core plate is pivotable about a pivot axis in the open position in order to remove the produced mouldings from the injection mould, or that a removal apparatus is provided, which is movable in the open position between the core plate and the cavity plate and is provided in order to remove produced mouldings from the cores or the cavities.

3. The injection mould according to claim 1, wherein two slider elementsare provided, which are arranged and configured in such a way that one neck ring of the neck-ring pair cooperates with the one slider element, while the other neck ring of the neck-ring pair cooperates with the other slider element, so that, when the injection mould is moved from the closed position into the open position, the neck ringsare moved from their holding position into the releasing position by a movement of the slider elements.

4. The injection mould according claim 1, wherein the cores and the cavities are arranged on a circular arc, and wherein the slider elements are preferably circularly arcuate in form.

5. The injection mould according to claim 3, wherein the cores and the cavities are arranged on a circular arc, wherein the slider elements are circularly arcuate in form, and wherein a single slider element of the two slider elements moves neck rings of neck-ring pairs such that neck rings are moved due to the movement of the single slider element, or that two single slider elements are associated with each moulding space, which only move the neck-ring pair of the respective moulding space.

6. The injection mould according to claim 1, wherein the cores and the cavities are arranged on a circular arc having a centrepoint angle, and wherein the centrepoint angle is less than 180° and preferably less than 120°.

7. The injection mould according to claim 1, wherein the cores and the cavities are arranged on two concentric circular arcs having different radii, and wherein the removal apparatus is preferably designed and configured in such a way that, using the same removal apparatus, mouldings from the cores or the cavities of both concentric circular arcs can be removed, in that the removal apparatus is adjusted to the radius of the circular arcs.

8. The injection mould according to claim 7, wherein ends of the cavities or cores which are jointly mounted on an outer circular arc of the concentric circular arcs span a first plane, wherein ends of the cavities or cores which are jointly arranged on an inner circular arc of the concentric circular arcs span a second plane, and wherein the first plane and the second plane are arranged parallel and spaced apart from one another.

9. The injection mould according to claim 5, wherein the cores and the cavities are arranged on a circular arc having a centrepoint angle, wherein the centrepoint angle is less than 180°, wherein a hotrunner is provided, which has an inlet for receiving a plasticized melt and outlets for delivering the plasticized melt to the cavities, wherein the hotrunner is arranged in such a way that the inlet is arranged in a centrepoint of the circular arc, wherein each cavity is associated with a hotrunner portion, which extends from a gate provided in the cavity to the inlet and wherein all hotrunner portions are the same length.

10. The injection mould according to claim 1, wherein the pairs consisting of cavity and associated core form at least two groups, and wherein the inner contour of the cavity and/or the outer contour of the core of the one group differ from the inner contour of the cavity and/or the outer contour of the core of the other group.

11. The injection mould according to claim 1, wherein a transfer chain having gripping elements is provided for holding a produced moulding, and wherein the core plate is configured such that, using the core plate, the produced mouldings can be transferred in the open position from the cores to the gripping elements, or wherein the removal apparatus is configured in such a way that, using the removal apparatus, the produced mouldings can, in the open position, be removed from the cores or from the cavities and transferred to the gripping elements.

12. The injection mould according to claim 11, wherein the transfer chain has at least one transfer chain portion, in which the gripping elements are arranged on a straight line and wherein, using the removal apparatus, the produced mouldings can be transferred within this transfer chain portion to the gripping elements.

13. The injection mould according to claim 2, wherein two slider elements are provided, which are arranged and configured in such a way that one neck ring of the neck-ring pair cooperates with the one slider element, while the other neck ring of the neck-ring pair cooperates with the other slider element, so that, when the injection mould is moved from the closed position into the open position, the neck rings are moved from their holding position into the releasing position by a movement of the slider elements, wherein a follow-up treatment element is provided, wherein the core plate or the removal apparatus transfers the mouldings removed from the injection mould to the follow-up treatment element, and wherein the follow-up treatment element transfers the mouldings to the transfer chain.

14. The injection mould according to claim 2, wherein the cores and the cavities are arranged on a circular arc, wherein the slider elements are circularly arcuate in form, and wherein the removal apparatus is configured as a circular arc and is moved between the cavity plate and the core plate by a rotational movement, preferably about a centrepoint of the circular arc.

15. An injection moulding system having at least one injection mould according to claim 1 and an extruder wherein the extruder is connected to the injection mould via a melt passage such that, during operation of the injection moulding system, the plasticized melt is guided from the extruder into the injection mould.

16. The injection moulding system according to claim 15, wherein the moulding space is arranged stationary opposite the extruder in the closed position of the cavity plate and the core plate.

17. The injection moulding system according to claim 15, wherein the injection moulding system has at least two injection moulds as well as injection cylinders associated with the at least two injection moulds, wherein the at least two injection moulds are connected to the injection cylinder via the melt passage, wherein the injection cylinders are connected to the extruder via at least one further melt passage, and wherein, during operation of the injection moulding system, the injection cylinders are alternately supplied with the plasticized melt from the extruder, such that either the one of the at least two injection moulds is in the closed position and the other injection mould of the at least two injection moulds is in the open position, or vice versa.

Description

[0049] Further advantages, features, and possible applications will become apparent from the following description of preferred embodiments and the associated drawings. Like components bear the same reference signs in this context.

[0050] FIG. 1 shows a schematic illustration of an embodiment of the injection mould according to the invention in a top plan view.

[0051] FIG. 2 shows a schematic illustration of a cross-section of a\ cut-out of the injection mould according to the invention at various timepoints of the demoulding process.

[0052] FIG. 3 shows a schematic illustration of an embodiment of the injection mould according to the invention, having separate slider elements.

[0053] FIG. 4 shows a schematic illustration of the hotrunner of an embodiment of the injection mould according to the invention.

[0054] FIG. 5 shows the schematic illustration from FIG. 4 with additional tubular heating bodies arranged about the hotrunner.

[0055] FIG. 6 shows a schematic illustration of an embodiment of the injection mould according to the invention, with the cores or cavities being arranged on two concentric circular paths.

[0056] FIG. 7 shows a schematic illustration of a cross-section of an embodiment of the injection mould according to the invention.

[0057] FIG. 8 shows a schematic illustration of an embodiment of the injection mould according to the invention with the follow-up treatment element.

[0058] FIG. 9 shows a schematic illustration of an embodiment of the injection moulding system according to the invention at a first method timepoint.

[0059] FIG. 10 shows the injection moulding system from FIG. 8 at a second method timepoint.

[0060] FIG. 11 shows the injection moulding system from FIG. 8 at a third method timepoint.

[0061] The injection mould according to the invention, which is shown in a top plan view in FIG. 1, has a cavity plate 2 with cavities 3 and a core plate 4 with cores 5. As can be seen from the cross-section of a tool cut-out in FIG. 2, the cavities 3 of the cavity plate 2 are supplied with plasticized melt via a hotrunner 9 in order to produce premoulds 1 when the cores 5 are arranged in the closed position of the tool in the cavities 3 (FIG. 2, left).

[0062] In FIG. 2, right, the injection mould is shown in an open position, i.e., no core 5 is arranged within a cavity 3. If, on the other hand, the cavity plate 2 or the core plate 4 is moved relative to the respective other plate into a closed position, a core 5 is arranged in each cavity 3 so that a moulding space for receiving the plasticized melt is formed (FIG. 2, left).

[0063] According to the embodiment shown in FIG. 1, the cores 5 and the cavities 3 are arranged on a circular track 6. A removal apparatus 14 is designed in a circular arc and can be moved in the open position of the core plate 4 and the cavity plate 2 by a rotational movement between the two plates 2, 4 in order to remove the produced premoulds 1 from the cores 5 or the cavity 3. When this is done, the removal apparatus 14 passes the premoulds 1 on to a transfer chain 12. The transfer chain 12 transports the produced premoulds to a subsequent machine portion in which the premoulds 1 are further processed.

[0064] For this purpose, the transfer chain 12 has gripping elements with which the produced premould pieces 1 are retained. As a result, a sorting of the produced premoulds 1 in the subsequent machining step is not necessary, rather the premoulds 1 are passed on directly in the correct orientation to the subsequent machining step.

[0065] The transfer chain 12 also has a transfer chain portion in which the gripping elements are arranged on a straight line, as can be seen in the figures. In the embodiments shown in FIGS. 1 to 5, the removal apparatus 14 transfers the produced premoulds 1 within this transfer chain portion to the gripping elements.

[0066] The injection mould according to the shown embodiments further has neck-ring pairs 15, 16, which are associated with each pair consisting of core 5 and cavity 3 and arranged on the core plate 4 and whose inner contour has an inner threading, in which case the inner contour corresponds to a portion of the outer contour of the premould 1 to be produced.

[0067] The neck-ring pair 15, 16 can in this case be moved back and forth between a holding position, in which the two neck rings 15, 16 of the neck-ring pair are in contact with one another, and a releasing position, in which the two neck rings 15, 16 of the neck-ring pair are not in contact with one another, by means of slide elements 7, 8. In the two illustrations on the left side of FIG. 2, the slider elements 7, 8 and the neck-ring pairs 15, 16 are located in the retaining position, respectively. In the second illustration on the right of FIG. 2, on the other hand, the slider elements 7, 8 perform a movement that shifts the neck-ring pairs 15, 16 from the holding position, and the releasing position shown on the right illustrations of FIG. 2.

[0068] The injection moulding operation process therefore proceeds such that the core 5 is initially arranged completely in the cavity 3, and a plasticized melt is filled in the moulding chamber. As soon as the plasticized melt begins to solidify, the core plate 4 is moved away from the cavity plate 2, whereby the premould is still initially held by the neck-ring pairs 15, 16 on the mould core 5. When the mould core 5 is guided out of the cavity 3, the slider elements 7, 8 perform a movement that moves the neck-ring pairs 15, 16 from the holding position into the releasing position so that the premould 1 can be removed.

[0069] The slider elements 7, 8 are configured such that a respective slider element 7 cooperates with a respective neck ring 15 of a neck-ring pair, while the other neck-ring 16 of the neck-ring pair cooperates with the other slider element 8. In this context, according to the embodiments shown in FIG. 1 as well as 4 to 6, a slider element 7 moves neck rings 15, 16 of different neck-ring pairs, such that a movement of the slider elements 7, 8 moves neck-ring pairs from their holding position into the releasing position or vice versa.

[0070] By contrast, FIG. 3 shows an embodiment in which each pair consisting of core 5 and cavity 3 has associated individual slider elements 7, 8 between the moulding space formed therefrom. Thus, each slider element 7, 8 causes only a movement of a single neck ring 15, 16 such that the neck-ring pairs are opened independently of the adjacent pairs consisting of core 5 and cavity 3.

[0071] The slider elements 7, 8 are moved in the radial direction to the circular path 6 during the opening movement, with the slider elements 7, 8 being configured such that they do not impede one another in their movement. For this purpose, the slider elements 7, 8 are designed in a circular arc.

[0072] Moreover, the cores 5 and the cavities 3 are arranged on a circular arc 6 such that a centrepoint angle of the circular arc 6 is less than 180°. This above all ensures that a pair consisting of core 5 and cavity 3 does not impede the opening movement of the slider elements 7, 8 when the movement of the slider element does not occur in the radial direction towards the circular path 6, for example, as shown in FIG. 1.

[0073] FIG. 4 shows how the cavities 3 are connected to the hotrunner 9 in order to guide a plasticized melt into the moulding spaces when the injection mould is in its closed position.

[0074] For this purpose, the hotrunner 9 has an inlet 10 for receiving the plasticized melt, as well as outlets 11 for delivering the plasticized melt to the cavities 3, with the hotrunner 9 being configured such that a hotrunner portion 9′ is associated with each cavity 3. In addition, the inlet 10 of the hotrunner is arranged at the centrepoint of the circular arc 6.

[0075] The hotrunner portion 9′ extends from the inlet 10 of the hotrunner 9 to a gate provided in the cavity 3 for the entry of the plasticized melt. By arranging the inlet 10 of the hotrunner 9 in the centrepoint the circular arc 6, all hotrunner portions 9′ are the same length. This offers the advantage that the plasticized melt is exposed to the same environmental influences at each cavity as it enters the cavities 3. This in turn leads to a higher homogeneity within an injection moulding operation of produced premoulds 1.

[0076] FIG. 5 also shows how tubular heating bodies 17 are arranged around the hotrunner 9 in order to maintain a homogeneous temperature in the hotrunner 9. The embodiment of the hotrunner 9 according to the invention offers the advantage that the tubular heating bodies 17 can be arranged in a serpentine manner around the hotrunner portions 9′, whereby there are no intersections of the tubular heater elements with one another or with the hotrunner portions 9′, such that a very homogeneous temperature distribution in the hotrunner 9 is ensured.

[0077] FIG. 6 shows a further embodiment of the injection mould according to the invention, with the cores 5 and the cavities 3 being arranged on a plane on two concentric circular arcs 6, 6′ having different radii.

[0078] An additional slider element 8′ is provided in this case, which moves the neck-ring pairs of the pairs consisting of cores 5 and cavities 3 arranged on the outer circular path 6 as well as the neck-ring pairs of the pairs consisting of cavities 3 and cores 5 arranged on the inner circular path 6′.

[0079] In order to demould the produced premoulds 1, therefore, in one embodiment, the slider elements 8′ and 8 are first removed from the slider element 7 so that the premoulds 1 can be demoulded on the outer circular path 6 and then the slider elements 7 and 8′ are subsequently removed from the slider element 8 so that the produced premoulds 1 can be demoulded on the inner circular path 6′. The demoulding process of the premoulds 1 on the outer circular arc 6 is thus time-delayed to the demoulding process of the premoulds 1 on the inner circular arc 6′.

[0080] The removed premoulds 1 are also passed on to a transfer chain 12 in this embodiment using the removal apparatus 14. In the embodiment shown in FIG. 6, however, the transfer chain 12 consists of two parallel paths, on which gripping elements are respectively arranged for receiving the premoulds 1. The premoulds 1 of the outer circular path 6 are in this case arranged on a different path of the transfer chain 12 than the premoulds 1 of the inner circular path 6′.

[0081] Alternatively, as shown in FIG. 7, the slider elements 7, 8 of the concentric circular arcs 6, 6′ are also arranged on different planes, such that the cavities 3 and cores 5 on the inner circular path 6′ as well as the cavities 3 and cores 5 on the outer circular path 6 each have associated pairs of slider elements 7, 8, 7′, 8′, and a demoulding of the premoulds 1 can occur simultaneously in that a slider element 7, 8, which is associated with the outer circular path 6, can be moved via a slider element 7′, 8′ associated with the inner circular path 6′.

[0082] In addition, the inner contours of the cavities 3 and/or the outer contours of the cores 5 can be configured differently on the inner circular path 6′ than on the outer circular path 6, for example, such that, in the closed position, a different forming space is formed, and premoulds 1 are produced having different outer and inner contours. It would also be conceivable, however, that the premoulds produced in the upper right quadrant of the injection mould will have a different outer contour than premoulds 1 produced in the upper left quadrant of the injection mould. In both embodiments, different premoulds 1 are produced in an injection moulding operation.

[0083] In FIG. 8, a further embodiment of the injection mould according to the invention is shown, whereby the injection mould substantially corresponds to the injection mould shown in FIG. 1, except that the removal apparatus 14 does not transfer the produced premoulds directly to the transfer chain 12, but rather initially to a follow-up treatment element 13, in which the produced premoulds 1 are cooled or otherwise subsequently treated. The follow-up treatment element 13 then transfers the subsequently treated premoulds 13 to the transfer chain 12.

[0084] FIGS. 9 to 11 show an embodiment of an injection moulding system according to the invention having two injection moulds, an extruder, 18 and two injection cylinders 19, 20 associated with the injection moulds.

[0085] The extruder 18 is connected to the injection cylinders 19, 20 via melt passages 21. The connection is configured by valves 22 such that either the one injection cylinder 19, 20 or the other injection cylinder 20, 19 is supplied with a plasticized melt.

[0086] FIG. 9 shows the case in which the injection cylinder 19 of the left of the two injection moulds is being filled with plasticized melt, while the premoulds 1 produced in the injection mould are transferred to the transfer chain 12 using the removal apparatus 14. The left injection mould is thus in the open position at the method timepoint shown in FIG. 9. The right of the two injection moulds, on the other hand, is in the closed position and is supplied with plasticized melt by the injection cylinder 20.

[0087] FIG. 10 then shows the method timepoint at which the injection event in the right injection mould is completed, i.e., the injection cylinder 20 is completely emptied. In the left injection mould, all produced premoulds 1 are also transferred to the transfer chain 12.

[0088] In FIG. 11, the correspondingly inverted behaviour to FIG. 8 is then shown. The injection cylinder 20 of the right injection mould is filled while the premoulds produced in this tool are transferred to the transfer chain 12 using the removal apparatus 14 of the right injection mould. For this purpose, the right tool is in its open position. At the same time, a new injection event takes place on the left injection mould, i.e., the left mould is in its closed position.

[0089] Thus, it can be enabled that the plasticized melt is extruded using the extruder 18 without interruption, and thus higher-quality premoulds 1 can be produced within a short time.

TABLE-US-00001 Reference signs 1 Premould 2 Cavity plate 3 Cavity 4 Core plate 5 Core 6 Curved path/outer circular arc 6′ Inner circular arc 7, 8, 7’, 8’ Slider elements 9 Hotrunner 9′ Hotrunner portion 10 Input of hotrunner 11 Outlet of hotrunner 12 Transfer chain 13 Follow-up treatment element 14 Removal apparatus 15, 16 Neck rings 17 Tubular heating body 18 Extruder 19, 20 Injection cylinder 21 Melt passage 22 Valve