DEVICE AND METHOD FOR INJECTION MOLDING

Abstract

An injection molding device (1) includes a center part (3) and a rotating device (2) for rotating the center part (3) in the injection molding device (1). The rotating device (2) includes a base (4) supported with respect to an injection molding machine. A thereto attached column (5) extends to an axial direction (z) above the base (4). A sleeve (6) coaxially surrounds the column (5) and is at least partially arranged in the center part (3). The sleeve (6) rotates with the center part (3) around the column (5). The column (5) is arranged removable with respect to the center part (3).

Claims

1. A rotating device arranged to hold and rotate a center part in an injection molding device of an injection molding machine, the rotating device comprising: a base supportable with respect to the injection molding machine; a column attached to the base and extending in an axial direction above the base, the column being removable with respect to the center part; a sleeve coaxially surrounding the column and at least partially arranged in the center part, wherein the sleeve is arranged to rotate with the center part around the column; one or more grooves arranged between the column and the sleeve to exchange liquid and/or gaseous media between the column and the sleeve; and a support arranged to fix the center part with respect to the base when the column is removed from the center part.

2. The rotating device according to claim 1, wherein the column is detachably interconnectable to the base.

3. The rotating device according to claim 2, wherein the column in its axial direction has a first diameter at a first position along the column and a second diameter at a second position along the column, the second diameter being different from the first diameter.

4. The rotating device according to claim 3, wherein the first position is closer to the base than the second position and wherein the first diameter is smaller than the second diameter such that the column can be removed from the sleeve in the center part in a direction away from the base.

5. The rotating device according to claim 4, wherein the column has a staggered design with at least two sections arranged coaxially and adjacent to each other in the axial direction, wherein a first section has the first diameter and a second section has the second diameter.

6. The rotating device according to claim 5, wherein the first section has at least one of the one or more grooves.

7. The rotating device according to claim 5, wherein a smooth transition surface is arranged between adjacent ones of the at least two sections.

8. The rotating device according to claim 1, wherein the base includes a fixture for the column.

9. The rotating device according to claim 8, wherein the fixture includes at least one supporting surface to support the center part in a radial or axial direction with respect to the base.

10. The rotating device according to claim 1, wherein the rotating device includes a drive with a stationary part and a rotary part, the drive being detachably interconnected to the center part by a quick release coupling.

11. The rotating device according to claim 10, wherein the stationary part of the drive is interconnectable to the injection molding machine by at least one tie bar.

12. The rotating device according to claim 10, wherein the stationary part of the drive is mechanically interconnectable to the column.

13. The rotating device according to claim 10, wherein a first part of the quick release coupling and a second part of the quick release coupling are self-centering with respect to each other.

14. The rotating device according to claim 1, wherein the column and the sleeve form part of a transfer unit.

15. A transfer unit for an injection molding device, the transfer unit comprising: a column having a first media interface in an area of said column's lower end when said column is in an operational orientation; and a sleeve having a second media interface in an area of said sleeve's upper end when said sleeve is in an operational orientation, said second media interface suitable to exchange liquid and/or gaseous media with a center part of the injection molding device, wherein the transfer unit is configured for assembly and disassembly independent of the center part.

16. The transfer unit according to claim 15, wherein the sleeve is detachably interconnectable to the center part and wherein the column is detachably interconnectable to a base.

17. The transfer unit according to claim 15, wherein the column has a staggered design with at least two sections arranged coaxially and adjacent to each other in an axial direction, and wherein a first section of the at least two sections has a first diameter and a second section of the at least two sections has a second diameter, the first diameter being different from the second diameter.

18. A method to disassemble an injection molding device, comprising: providing an injection molding device having a center part and a rotating device arranged to hold and rotate the center part in the injection molding device, wherein the rotating device includes a base supported with respect to an injection molding machine, a column attached to the base and extending in an axial direction above the base, and a sleeve coaxially surrounding the column and at least partially arranged in the center part, the sleeve configured to rotate with the center part around the column; and separating the column from the center part while the column or the center part remains in the injection molding device.

19. The method according to claim 18, further comprising: detachably fixing the center part with respect to the base; releasing a fixture holding the column with respect to the base; and removing the column from the center part in a first direction away from the base.

20. The method according to claim 18, further comprising: prior to releasing the fixture, exchanging liquid and/or gaseous media between the column and the sleeve via one or more grooves arranged between the column and the sleeve.

Description

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0023] The herein described invention will be more fully understood from the detailed description given herein below and the accompanying drawings which should not be considered limiting to the invention described in the appended claims. The drawings are showing:

[0024] FIG. 1 shows a first variation of an injection molding device in a perspective manner;

[0025] FIG. 2 shows the injection molding device according to FIG. 1 in a partially disassembled manner;

[0026] FIG. 3 shows the injection molding device according to FIG. 1 in an exploded view;

[0027] FIG. 4 shows a second variation of the injection molding device in a partially dismantled view;

[0028] FIG. 5 shows a third variation of an injection molding device in a perspective manner and partially cut;

[0029] FIG. 6 shows detail D according to FIG. 4 in a magnified manner;

[0030] FIG. 7 shows detail E according to FIG. 4 in a magnified manner;

[0031] FIG. 8 shows the injection molding device according to FIG. 5 in a partially disassembled manner.

DETAILED DESCRIPTION OF THE INVENTION

[0032] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

[0033] FIG. 1 shows a variation of an injection molding device 1 according to the invention in a perspective manner from above. FIG. 2 shows the injection molding device 1 according to FIG. 1 in a partially dismantled position. FIG. 3 shows the injection molding device 1 in an exploded view. FIG. 4 shows the injection molding device 1 in another partially dismantled position. FIG. 5 shows a further variation of the injection molding device 1 in a perspective, partially cut view, such that the inside becomes apparent. FIG. 6 shows detail D according to FIG. 5 and FIG. 7 shows detail E according to FIG. 5. FIG. 8 shows the variation according to FIG. 5 in a partially dismantled state.

[0034] The injection molding device 1 comprises a center part 3 and a rotating device 2 for holding and rotating the center part 3 in the injection molding device 1 when then injection molding device 1 is in an open position.

[0035] The injection molding device 1 can be used for highly efficient injection molding of plastic products. As indicated in FIG. 1 it normally comprises an injection mold 32 with a first outer mold half 33 (schematically indicated by dotted lines) and a thereto along upper and lower tie bars 17, 18 of an injection molding machine in a first direction (x-direction) relatively to the first outer mold half displaceable second outer mold half 34 (schematically indicated by dotted lines). Between the first and the second outer mold half a center part 3 is arranged rotatable around a center axis 27 extending in vertical direction (z-direction). The center part 3 comprises in the shown variation four side faces 28 which are arranged in pairs parallel to each other and which each carry an inner mold half 35 (schematically indicated by dotted lines). The inner mold halves 35 in a closed position of the injection molding device 1 interact with the first and the second outer mold halves in a first and in a second separation plane 36, 37 forming cavities suitable to receive melted plastic material injected through a sprue channel into the cavities to form objects consisting at least partially from the melted plastic material. After the melted plastic material has sufficiently cured, the injection molding device 1 is opened in the area of the first and second separation planes 36, 37, if appropriate parts are ejected and the center part 3 is rotated by an appropriate angle, here at 90°, around the center axis 27 such that another two inner mold halves 35 can be interconnected to the first and second outer mold halves 33, 34 forming cavities as described above.

[0036] As visible in the drawings the rotating device 2 comprises a base 4 which in the shown variation is in x-direction linearly displaceable supported on a machine bed (not shown in the drawings) via linear bearings 29 and rails 30 attached to the machine bed. As visible in FIGS. 3 and 4, a column 5 is attached to the base and extends in axial direction above the base 4. A sleeve 6 is arranged on and coaxially surrounds the column 5. The sleeve 6 is arranged in and herein fixedly interconnected to the center part 3. Good results can be achieved when the center part is made from a material which has a lower density then the material of the sleeve. Good results can be achieved when the sleeve 6 is made from steel or the like and the center part 3 is made from aluminum or the like. The sleeve 6 is attached to and rotates with the center part 3 around the column 5 which is attached to the base 4. Grooves arranged between the sleeve and the column are used to exchange liquid and/or gaseous media between the column and the sleeve, respectively the center part.

[0037] As best visible in FIG. 2, FIG. 5 and FIG. 8 the rotating device 2 comprises a drive 19 with a non-rotary part 20 and a rotary part 21 which is interconnected to the rotating center part 3 by a quick release coupling 22 such that the drive 19 is easily detachable from the center part 3 as schematically indicated in FIG. 2 and FIG. 8. Good results can be achieved when the drive 19 sits above the center part 3, respectively the column 5 in a coaxial manner. The stationary part 20 of the drive 19 is interconnected via a yoke 16 to the injection molding machine by at least one upper tie bar 18. The stationary part 20 of the drive 19 can be interconnected detachably to the column 5. The quick release coupling 22 comprises a first and a thereto interconnectable second part 23, 24 which transfer torque between the drive 19 and the rotatable center part 3. For additional centering the first and the second part of the quick release coupling can be self-centering with respect to each other. The drive may comprise a gear box which is preferably arranged on the stationary side.

[0038] In the variation according to FIGS. 5 through 8, the drive 19 is mounted on an adapter plate 46 which is attached to an opening 38 of the yoke 16. As visible in FIG. 8, this offers the advantage that drive 19 can be removed together with the adapter plate 46 without dismantling the yoke 16. The opening 38 preferably has a diameter such that the column 5 and the sleeve 6 can then be removed in an upward direction (z-axis) from the center part 3. In the shown variation, the column 5 and the sleeve 6 form a transfer unit 43 which can be removed from the center part 3 after releasing fastening screws 47 accessible from below at the base 4. At a later stage, they can be separated from each other e.g. for maintenance reasons outside the center part 3. The transfer unit 43 can be assembled and disassembled independent of the center part 3. The transfer unit preferably comprises a first and a second media interface 39, 40 through which liquid and/or gaseous media can be exchanged between the outside and the inner mold halves attached to the center part. Therefore, the center part 3 may comprise a third and the base a fourth media interface 41, 42 which are interconnectable to the first and the second media interface 39, 40. Good results can be achieved when the second media interface 40 is arranged at the upper end of the sleeve 6, while the first media interface 39 is arranged at the lower end of the column. Alternatively, or in addition pipes 45 for media transfer may be interconnected directly to the lower end of the column, respectively the first media interface 39 in the region of the lower end of the column 5. At least the second and the third media 40, 41 interface may be interconnected indirectly to each other via a link element 44, e.g. in the form of a ring which in a mounted position interconnects to the upper end of the sleeve 6 with the center part 3 and transfers media there between.

[0039] In the variations according to FIGS. 3 and 4 the column 5 is arranged removable with respect to the center part 3, respectively the sleeve 6. In the variation according to FIG. 3 the column 5 is detachable from the center part 3 in a downward direction while in the variation according to FIG. 4 the column 5 is detachable in an upward direction as will be explained in more detail hereinafter. In both variations, the column 5 is arranged detachable from the base 4 by removing fastening means 31 first.

[0040] The columns 5 of both variations are having in axial direction a variable diameter. Depending on the design the variable diameter can be e.g. linearly varying. Alternatively, or in addition as shown here the column 5 can have a staggered design, with at least two sections 8 arranged coaxially in and adjacent to each other and with respect to the axial direction of the column 5.

[0041] In the variation as shown in FIG. 4 the sections 8 have decreasing diameters in the direction towards the base 4 of the rotation device 2 such that the column 5 can be removed from the center part 3, respectively the sleeve 6 in an upward direction as shown away from the base 4. The column 5 is therefore interconnected detachably to the base 4.

[0042] In the variation according to FIG. 3 the decreasing diameter is arranged in the opposite direction, i.e., smaller diameters are further away from the base 4. Thereby it would be possible to leave the column attached to the base and remove the center part 3 in an upward direction away from the base 4. Alternatively, or in addition a separation of the center part 3 from base 4 can be achieved by designing the sleeve 6 removable from the center part 3 as such.

[0043] In the shown variation at least one section 8 comprises at least one groove 7 interconnected to one or several channels 14 arranged in the column 5 and/or the sleeve 6. The grooves 7 are used to exchange liquid and/or gaseous media between the column 5 and the sleeve 6. The at least one groove 7 can be arranged along on outer surface of the column 5 and/or a thereto corresponding inner surface of the sleeve 6. Normally on both sides adjacent to the at least one groove for the liquid and/or gaseous media a groove is arranged to receive a sealing means. Good results can be achieved when between two adjacent sections a smooth transition surface 9 is arranged which supports assembly and disassembly of the sleeve with respect to the column.

[0044] As visible in FIG. 4 the base 4 comprises a detachable fixture 10 for the column 5 which allows to detach the column 5 from the base 4 even while the center part 4 remains on the base 4. This offers significant advantage in that maintenance becomes possible without removing the heavy and bulky center part 3 from the rotating device 2, i.e., the center part 3 can remain in the injection molding device 1 which service is made to the rotating device.

[0045] In the variation according to FIG. 4 the fixture 10 for the column 5 comprise at least one radial and/or axial supporting surface 11 to support the center part 3 directly and/or via the sleeve 6 in radial and/or axial direction with respect to the base 4. The radial and/or axial supporting surface receive at least one bearing 12, 13. If appropriate additional fixation means 15 can be foreseen by which the center part 3 can be fixed temporarily to the base 4 to provide a sufficiently stable support while the column 5 is removed from the center part 3. The center part as well as the base comprise thereto corresponding abutments. The fixation means 15 can be in the form of a threaded support preferably arranged between the center part 3 and the base 4. The fixation means 15 must be able to securely hold and position the weight of the center part 3 and the thereto attached elements with respect to the base in a manner, such that the column 5 can be removed from the sleeve 6, respectively the center part and vice-versa.

[0046] Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the Spirit and scope of the invention.