Injection Molding Tool

Abstract

The invention relates to an injection molding tool having a nozzle plate which comprises a first through-hole in an axial direction, in which first through-hole an injection molding nozzle is arranged extending in the axial direction. The injection molding tool further includes a cavity plate which comprises at least one cavity half into which a second through-hole, which is arranged in the cavity plate and coaxially with respect to the first through-hole, opens. A nozzle bushing, which encloses the injection molding nozzle at least in certain regions in the assembled state, is arranged in the second through-hole. The nozzle bushing is operatively connected to the cavity plate and/or nozzle plate by way of an operative connection means, wherein the nozzle bushing and the operative connection means are operatively connected to one another at least in the axial direction.

Claims

1. An injection molding tool, having a. a nozzle plate which comprises a first through-hole in an axial direction, in which the first through-hole an injection molding nozzle is arranged extending in the axial direction, and b. a cavity plate which comprises at least one cavity half into which a second through-hole, which is arranged in the cavity plate and coaxially with respect to the first through-hole, opens, wherein c. a nozzle bushing, which encloses the injection molding nozzle at least in regions in the assembled state, is arranged in the second through-hole, wherein d. the nozzle bushing is operatively connected to the cavity plate and/or the nozzle plate by an operative connection means, wherein e. the nozzle bushing and the operative connection means are operatively connected to one another at least in the axial direction.

2. The injection molding tool according to claim 1, wherein the operative connection means is arranged between the nozzle plate and the cavity plate.

3. The injection molding tool according to claim 1, wherein the operative connection means a. includes a flange plate which comprises a central opening in which the nozzle bushing is arranged, wherein the flange plate is fastened to the nozzle plate and/or the cavity plate in the axial direction by means of one or more screws, or b. includes a threaded bushing which comprises a central opening in which the nozzle bushing is arranged, wherein the threaded bushing is screwed to the nozzle plate and/or the cavity plate in the axial direction by way of a threaded connection.

4. The injection molding tool according to claim 3, wherein the central opening can slide onto the nozzle bushing with the operative connection means in two orientations relative to the nozzle bushing.

5. The injection molding tool according to claim 1, wherein that the operative connection means comprises a first stop surface and the nozzle bushing comprises a second stop surface, which, in the assembled state, prevents the nozzle bushing from being displaced in relation to the cavity plate counter to the direction of the melt flow.

6. The injection molding tool according to claim 1, wherein a securing means cooperates with the nozzle bushing in the assembled state and prevents the nozzle bushing from being displaced in relation to the operative connection means in the direction of the melt flow.

7. The injection molding tool according to claim 6, wherein the securing means includes at least one of the following elements: a snap ring, and a threaded nut.

8. The injection molding tool according to claim 1, wherein that the nozzle bushing comprises a first sealing means, which cooperates in a sealing manner with an inner surface of the second through-hole in the assembled state.

9. The injection molding tool according to claim 8, wherein the first sealing means includes at least one of the following elements: a circumferential bead with a first sealing surface, and an O-ring.

10. The injection molding tool according to claim 8, wherein the first sealing means is arranged in the longitudinal direction of the nozzle bushing, in a range of 20% to 80%, between a cavity-side end of the nozzle bushings; and a second stop surface.

11. The injection molding tool according to claim 8, wherein a second sealing means is arranged, in the assembled state, between the nozzle bushing and an inner surface of the second through-hole and/or the injection molding nozzle.

12. The injection molding tool according to claim 1, wherein the nozzle bushing is configured so as to taper in cross section, at least in one portion, in the direction of the melt flow.

13. The injection molding tool according to claim 1, wherein the nozzle bushing comprises a seat for the cavity-side end of the injection molding nozzle.

14. The injection molding tool according to claim 13, wherein the nozzle bushing includes a third sealing means, which is arranged between the cavity-side end of the injection molding nozzle and the nozzle bushing and cooperates in a sealing manner with the injection molding nozzle.

15. The injection molding tool according to claim 1, wherein, between the first sealing means and the second sealing means, an inner surface of the second through-hole and an outer surface of the nozzle bushing delimit part of a coolant channel.

16. The injection molding tool, according to claim 1, wherein the nozzle plate; and the cavity plate delimit a cable channel which is arranged between them and through which cabling for the injection molding nozzle is routed.

17. The injection molding tool according to claim 1, wherein an anti-rotation means cooperates with the nozzle bushing and the operative connection means and/or the nozzle plate and/or the cavity plate and prevents the nozzle bushing from rotating about the axial direction.

18. A nozzle bushing and operative connection means for use with the injection molding tool according to claim 1.

Description

[0023] Aspects of the invention are explained in more detail on the basis of the exemplary embodiments shown in the figures below and the associated description. In the figures:

[0024] FIG. 1 shows a perspective view of a first variation of an injection molding tool according to the invention with a detail showing the internal construction;

[0025] FIG. 2 shows an enlarged illustration of the detail from FIG. 1, which is denoted by D in said figure;

[0026] FIG. 3 shows a first variation of a nozzle bushing according to the invention with a first variation of an operative connection means in an exploded illustration;

[0027] FIG. 4 shows the nozzle bushing with the operative connection means of FIG. 3, which has been slid onto the nozzle bushing in a further orientation, with a detail illustrating the internal construction;

[0028] FIG. 5 shows the nozzle bushing of FIG. 3 with a second variation of an operative connection means in an exploded illustration;

[0029] FIG. 6 shows the nozzle bushing of FIG. 3 with the second variation of the operative connection means of FIG. 5, which has been slid onto the nozzle bushing in a further orientation, with a detail illustrating the internal construction;

[0030] FIG. 7 shows a perspective sectional illustration of a second variation of an injection molding tool with a second variation of the nozzle bushing; and

[0031] FIG. 8 shows a perspective view of the first variation of the injection molding tool of FIG. 1 in an exploded illustration with the nozzle bushing and the operative connection means of FIG. 3.

[0032] FIGS. 1, 2, and 8 show a first variation of an injection molding tool 1 according to the invention. The injection molding tool 1 includes a nozzle plate 2, as can be seen in FIG. 7, which comprises a first through-hole 3 passing through it in an axial direction (z-direction). Furthermore, the injection molding tool 1 includes a cavity plate 5, this comprising at least one cavity half 6 into which a second through-hole 7, which is arranged in the cavity plate 5 and passes through it, opens. The second through-hole 7 is arranged coaxially with respect to the first through-hole 3. An injection molding nozzle 4 is arranged in the first through-hole 3 extending in the axial direction z. The injection molding nozzle 4 also runs from the first through-hole 3 into the second through-hole 7. A first variation of a nozzle bushing 8, which encloses the injection molding nozzle 4 at least in certain regions in the assembled state, is depicted arranged in the second through-hole 7, as can be seen in FIGS. 1, 2.

[0033] A variation of the cavity plate 5, in which a plurality of second through-holes 7 are arranged, can be seen in FIGS. 1 and 8. The cavity plate 5 and the nozzle plate 2 adjoin one another in the assembled state, which is shown in FIG. 7, in a plane xy perpendicular to the axial direction z. In some variants, the cavity plate 5 and the nozzle plate 2 delimit an interposed cable channel 31. The cable channel 31, which runs in the nozzle plate 3, can be seen in FIG. 7. Cabling 32 for, for example, the nozzle heater of the injection molding nozzle 4 is laid in this cable channel 31.

[0034] FIGS. 1, 2, 7 and 8 show various embodiments of the injection molding tool 1 and the nozzle bushing 8, which is operatively connected to the cavity plate 5 or nozzle plate 2 by way of an operative connection means 9. In this case, the operative connection means 9 is arranged between the nozzle plate 2 and the cavity plate 5. Furthermore, the nozzle bushing 8 and the operative connection means 9 are operatively connected to one another at least in the axial direction z.

[0035] A first variation of the nozzle bushing 8 with various embodiments of the operative connection means 9 is shown in FIGS. 3 to 6. In FIGS. 3 and 4, the operative connection means 9 is a flange plate 12. This flange plate comprises a central opening 13 in which the nozzle bushing 8 is arranged in the assembled state. In the variations illustrated, the flange plate 12 is fastened to the nozzle plate 2 or the cavity plate 5 in the axial direction z by means of a plurality of screws 14. In FIGS. 5 and 6, the operative connection means 9 is a threaded bushing 15. This threaded bushing comprises a central opening 13 in which the nozzle bushing 8 is arranged in the assembled state. The threaded bushing 15 is fastened to the nozzle plate 2 or the cavity plate 5 in the axial direction z by means of a threaded connection.

[0036] In order to establish an operative connection between the nozzle bushing 8 and the operative connection means 9, the operative connection means 9 comprises a first stop surface 10 and the nozzle bushing 8 comprises a second stop surface 11. In the assembled state, these stop surfaces 10, 11 prevent the nozzle bushing 8 from being displaced in relation to the cavity plate 5 and/or nozzle plate 2 counter to the direction of the melt flow (?z). A securing means 17, which cooperates with the nozzle bushing 8 in the assembled state, prevents the nozzle bushing 8 from being displaced in relation to the operative connection means 9 in the direction of the melt flow (?z). In the variations shown, the securing means 17 includes a snap ring 18. The cooperation between the operative connection means 9 and the securing means 17 has the effect of retaining and/or positioning the nozzle bushing 8 in relation to the cavity plate 5 and/or nozzle plate 2 at least in the axial direction z.

[0037] In FIGS. 5 and 6, and also FIGS. 3 and 4, the same components are depicted in each case, but the operative connection means 9 has been slid onto the nozzle bushing 8 in two different orientations, such that the operative connection means 9 can be connected to the cavity plate 5 or the nozzle plate 2.

[0038] It is apparent in FIGS. 1, 2, 4 and 6 to 8 that the nozzle bushing 8 is configured so as to taper in cross section, at least in one portion, in the direction of the melt flow (?z). Furthermore, the nozzle bushing 8 comprises a seat 26 for the cavity-side end of the injection molding nozzle 4. In this way, in the assembled state, the nozzle bushing 8 functions as a positioning aid, protection and holder for the injection molding nozzle 4 used. In addition, the nozzle bushing comprises a first sealing means 16, which cooperates in a sealing manner with an inner surface 20 of the second through-hole 7 in the assembled state. The first sealing means is arranged on an outer surface 29 of the nozzle bushing 8 and includes a circumferential bead 21 with a first sealing surface 22. Alternatively, the first sealing means 16 includes an O-ring, as illustrated in FIG. 7. The first sealing means 16 is arranged in the longitudinal direction z of the nozzle bushing 8, in a range of 20% to 80%, between the cavity-side end 24 of the nozzle bushings 8 and the second stop surface A variation of a second sealing means 25, which is arranged between the nozzle bushing 8 and an inner surface 20 of the second through-bore 7 and/or the injection molding nozzle 4 in the assembled state, can be seen in each case in FIGS. 2 and 7. In this case, the second sealing means 25 is arranged in the region of the tapered portion of the nozzle bushing 8. FIGS. 2, 4, 6 and 7 show a nozzle bushing 8 with a third sealing means 28, which is arranged in the region of the outlet opening of the injection molding nozzle 4 between the cavity-side end 27 of the injection molding nozzle 4 and the nozzle bushing 8 and cooperates in a sealing manner with the injection molding nozzle 4. In the variations illustrated, the third sealing means 28 includes a circumferential sealing surface which makes contact with the injection molding nozzle 4 in a circumferential manner.

[0039] FIG. 7 shows a perspective sectional illustration of a second variation of an injection molding tool 1 with an actively cooled second embodiment of the nozzle bushing 8. A hollow space running around the nozzle bushing 8 between the first and the second sealing means 16, 25 is part of a coolant channel 30, the supply and discharge lines of which are arranged in the cavity plate. Furthermore, part of the coolant channel 30 is delimited by an inner surface 20 of the second through-hole 7 and an outer surface 29 of the nozzle bushing 8.

[0040] FIGS. 3 to 6 show a nozzle bushing 8 which is rotationally symmetrical about its longitudinal axis. However, in variations, the injection molding tool 1 includes an anti-rotation means 33, which cooperates with the nozzle bushing 8 and the operative connection means 9 and/or the nozzle plate 2 and/or the cavity plate 5 and prevents the nozzle bushing 8 from rotating about the axial direction z or about its longitudinal axis. This is illustrated in FIG. 7.

LIST OF REFERENCE DESIGNATIONS

[0041] 1 Injection molding tool [0042] 2 Nozzle plate [0043] 3 First through-hole [0044] 4 Injection molding nozzle [0045] 5 Cavity plate [0046] 6 Cavity half [0047] 7 Second through-hole [0048] 8 Nozzle bushing [0049] 9 Operative connection means [0050] 10 First stop surface [0051] 11 Second stop surface [0052] 12 Flange plate [0053] 13 Central opening (operative connection means) [0054] 14 Screws [0055] 15 Threaded bushing [0056] 16 First sealing means (nozzle bushing) [0057] 17 Securing means [0058] 18 Snap ring [0059] 20 Inner surface (second through-hold) [0060] 21 Bead [0061] 22 First sealing surface [0062] 24 Cavity-side end/nozzle bushing tip [0063] 25 Second sealing means [0064] 26 Seat [0065] 27 Cavity-side end of the injection molding nozzle 4 [0066] 28 Third sealing means [0067] 29 Outer surface (nozzle bushing [0068] 30 Coolant channel [0069] 31 Cable channel [0070] 32 Cabling [0071] 33 Anti-rotation means