HOT RUNNER NOZZLE FOR LATERAL GATING

Abstract

A hot runner nozzle for the lateral gating of plastic components has a nozzle body and a pressure lid. Tip elements are arranged between the nozzle body and the pressure lid, which are each inserted into a recess of the nozzle body and are each penetrated by a movable closure needle having a tip, which in at least one operating position protrudes in each case over an outer circumferential edge of the nozzle body. The closure needles each include, on their ends facing away from the tip, a coupling means, which is coupled to a drive means for moving the closure needles. The tip elements are supported on their side facing away from the respective tip of the closure needles on a buttress element inserted between the nozzle body and the pressure lid.

Claims

1-25. (canceled)

26. A hot runner nozzle for lateral gating of plastic components, the hot runner nozzle comprising: a nozzle body; a pressure lid; and tip elements arranged between the nozzle body and the pressure lid, wherein each of the tip elements are inserted into a recess of the nozzle body and are each penetrated by a movable closure needle having a tip, which in at least one operating position protrudes in each case over an outer circumferential edge of the nozzle body, wherein the closure needles each include, on their ends facing away from the tip, a coupling means, which is coupled to a drive means for moving the closure needles, wherein the tip elements are supported on their side facing away from the respective tip of the closure needles on a removable buttress element inserted between the nozzle body and the pressure lid.

27. The hot runner nozzle of claim 26, wherein the tip elements each include a heat conduction body and the respective closure needle completely penetrating the heat conduction body.

28. The hot runner nozzle of claim 27, wherein the tip elements include a needle seal and guide sleeve, which the respective closure needle completely penetrates.

29. The hot runner nozzle of claim 26, wherein the removable buttress element includes a removal means for removing the removable buttress element.

30. The hot runner nozzle of claim 27, further comprising: a seal sleeve section formed on the heat conduction body to support the tip element on the side facing away from the removable buttress element on a tool, which is integrally formed with the heat conduction body or is formed as a separate sleeve from the heat conduction body.

31. The hot runner nozzle of claim 30, wherein the seal sleeve section consists of a material of lower thermal conductivity than the heat conduction body.

32. The hot runner nozzle of claim 26, wherein the nozzle body is cylindrical or polygonal, and two or more of the tip elements are distributed on an outer circumference of the nozzle body, wherein the removable buttress element is arranged in each case between the drive means and the tip elements.

33. The hot runner nozzle of claim 28, wherein the removable buttress element includes at least one bridge section, wherein the at least one bridge section is penetrated by one of the closure needles, wherein an end of the closure needle facing away from the tip protrudes through the at least one bridge section, where the coupling means is coupled with the drive means.

34. The hot runner nozzle of claim 33, wherein the at least one bridge section of the removable buttress element overlaps a step of the heat conduction body or the needle seal and guide sleeve of the respective tip element.

35. The hot runner nozzle of claim 26, wherein the removable buttress element is configured in such a way that it is installable after the tip elements with respect to time and is removable before the tip elements.

36. The hot runner nozzle of claim 26, wherein the coupling means is a one-part or multipart shaped element, which each engage in one of multiple slotted guides of the drive means.

37. The hot runner nozzle of claim 36, wherein the slotted guides of the drive means are oriented in sections or completely obliquely or in a curve in relation to a movement direction of the drive means.

38. The hot runner nozzle of claim 28, wherein the needle seal and guide sleeve is screwed into the heat conduction body.

39. The hot runner nozzle of claim 28, wherein the needle seal and guide sleeve has a through hole configured for sealed guiding of the closure needle.

40. The hot runner nozzle of claim 28, wherein a hole is formed in the heat conduction body, which the closure needle penetrates, wherein a ring channel, which is configured to conduct through melt, is formed around the closure needle between an end of the heat conduction body facing toward the tip and the needle seal and guide sleeve.

41. The hot runner nozzle of claim 40, wherein at least one feed hole extending obliquely to the ring channel is formed in the heat conduction body to feed melt from the nozzle body into the ring channel.

42. The hot runner nozzle of claim 26, wherein the tip elements are pressed by the pressure lid in a direction of a main extension direction on the nozzle body and wherein a surface of the tip element, at least in a heated state of the hot runner nozzle, supports itself on a web of the removable buttress element.

43. The hot runner nozzle of claim 26, wherein the pressure lid secures the separate removable buttress element in an installed state against impermissible displacement in a main extension direction.

44. The hot runner nozzle of claim 26, wherein the removable buttress element includes a ring-shaped, cuboid, or polygonal base body, on which at least two tip elements support themselves directly or indirectly.

45. The hot runner nozzle of claim 26, wherein multiple removable buttress elements are inserted between the nozzle body and the pressure lid.

46. The hot runner nozzle of claim 26, wherein a support of a tip element on the removable buttress element is arranged between the tip of the closure needle and the drive means.

47. The hot runner nozzle of claim 26, wherein the drive means is configured to position the respective closure needle in different operating positions.

48. The hot runner nozzle of claim 26, wherein the drive means is configured to position the respective closure needle in different operating positions and the position of the closure needle is approachable at a predetermined speed or a speed curve.

49. A method for removing one or more tip elements of a hot runner nozzle, having a nozzle body and a pressure lid, wherein the tip element or elements are arranged between the nozzle body and the pressure lid, which are each inserted into a recess of the nozzle body and are each penetrated by a movable closure needle having a tip, each of which protrudes in at least one operating position beyond an outer circumferential edge of the nozzle body, wherein the closure needles each have, on their ends facing away from the tip, a coupling means, which is coupled with a drive means for moving the closure needles, wherein the tip element or elements are supported on a buttress element inserted between the nozzle body and the pressure lid, the method comprising: 100) removing the pressure lid; 200) after step 100), the drive means is removed, whereby the respective tip element is decoupled from the drive means; 300) after step 200), the buttress element is removed; and 400) after step 300) the one or more tip elements are removed.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0041] In the following, the invention is explained in greater detail on the basis of exemplary embodiments with reference to the drawings. The solutions of the illustrated figures are particularly advantageously suitable for the nozzle bodies and tip elements illustrated in the following figures. However, the invention is not restricted to these special embodiments but can also be implemented in other ways in the scope of the claims. In the figures:

[0042] FIGS. 1a-c show in a) a perspective view of a section of a hot runner device having hot runner nozzle having a multipart nozzle body having tip elements inserted therein and a closure needle in addition to a drive device for the closure needle and in b) the arrangement from a) without pressure lid and in c) an installation of a tip element using an installation tool;

[0043] FIG. 2 shows an exploded view of the elements from FIG. 1a;

[0044] FIG. 3 shows a sectional view of a tip element;

[0045] FIGS. 4a, b show in a) a perspective view of the hot runner nozzle from FIG. 1a without pressure lid and drive ring but having some tip elements and having a buttress and pressure ring and in b) shows a top view of the arrangement from a);

[0046] FIGS. 5a, b shows the arrangement from FIG. 4 with two tip elements without pressure lid with a drive lever, in a) in a top view and in b) in section;

[0047] FIG. 6 shows a section through a hot runner nozzle of the type according to FIGS. 1 and 5 on a tool;

[0048] FIG. 7 shows in a), b), and c) a top view of a section of a pressure lid of a hot runner nozzle having a region in partial section of a tip element on a mold cavity of a tool in three different operating positions; and

[0049] FIG. 8 shows in a) and b) a perspective view and an exploded view of a further hot runner nozzle.

DETAILED DESCRIPTION

[0050] Terms such as “top” or “bottom” are not to be understood as restrictive, but solely relate to the respective arrangement and alignment in the figures.

[0051] FIG. 1 shows a section of a hot runner device having a hot runner nozzle 1, which is designed for lateral gating of plastic components.

[0052] For this purpose, the hot runner nozzle 1 for lateral gating includes a nozzle body 2 and a pressure or clamping lid 3 releasably fastened on the nozzle body 2.

[0053] The hot runner nozzle 1 can furthermore include a nozzle holder 4, using which the hot runner nozzle or its nozzle body 2 can be fixed on further elements (not shown here) of the hot runner device.

[0054] The pressure lid 3 can be releasably fastened on the nozzle body 2 using a fastening means, for example formed as one or more screws 5 (FIG. 2).

[0055] The nozzle body 2 can have an approximately cylindrical base shape, so that it then has an approximately cylindrical outer jacket having a lateral surface MF. Such an exemplary embodiment is shown in FIGS. 1a-c. However, the invention is not restricted thereto. The nozzle body 2 can also have a different base shape. It is thus formed approximately cuboid in the exemplary embodiment of FIG. 8, so that it has a correspondingly cuboid lateral surface.

[0056] The nozzle body 2 has a main extension direction HE by definition. In a cylindrical base shape, this can be the longitudinal axis of the cylinder.

[0057] The gating or extrusion of plastic melt takes place laterally, in particular perpendicularly, to the main extension direction HE, which can furthermore mean here that the extrusion of the plastic takes place precisely or approximately perpendicularly to the lateral surface MF. Melt can advantageously be ejected at multiple points of the lateral surface MF — angularly offset in the circumferential direction — perpendicularly to the lateral surface MF using the hot runner nozzle 1.

[0058] To implement this, various functional elements and functional contours are formed between the nozzle body 2 and the pressure lid 3.

[0059] The nozzle body 2 thus has an axial side at its end facing toward the pressure lid 3, which is provided with at least one or more recesses 6, arranged radially circumferentially distributed on the axial side here by way of example, for arranging and receiving tip elements 7. Corresponding recesses are formed in the pressure lid 3 (not shown here).

[0060] One of the tip elements 7 is arranged in each of the recesses 6.

[0061] The following description of the tip elements 7 also applies for the further tip elements of FIGS. 1 to 8. When the location of only one of the tip elements or at other points multiple of the tip elements 7 is moreover described hereinafter, it is obvious that these features can also each be provided in the case of multiple tip elements 7.

[0062] The tip elements 7 — see FIG. 3 — each include a heat conduction body 8 (as a base body). The heat conduction body 8 structurally also forms a type of base body of the respective tip element 7.

[0063] The heat conduction body 8 furthermore includes a seal sleeve section 9. The seal sleeve section 9 can be formed integrally with the heat conduction body 8 (as shown here) or as a sleeve element separate therefrom (not shown here, see, for example, WO 2010/127965 A).

[0064] The heat conduction body 8 can have a type of cuboid shape, wherein the individual cuboid heat conduction bodies 8 can be approximately radially aligned on the nozzle body 1 (if the nozzle body is cylindrical).

[0065] Each heat conduction body 8 can have a hole 10 penetrating it longitudinally. This hole 10 can be formed stepped. The hole 10 can thus include hole sections 10a, b, c — three here — of different diameters.

[0066] At its one end, the heat conduction body 8 can include a type of projection 11. This projection 11 can be formed cylindrical. It is oriented toward a tool or a mold cavity (FIG. 7), but preferably does not touch it. At its other end, a seal and guide sleeve 12 — also referred to synonymously in short as guide sleeve 12 hereinafter — can be inserted into the heat conduction body 8, which is formed here as a threaded sleeve having a through hole for the sealed guiding of the closure needle 14. The seal and guide sleeve 12 can be screwed into a hole section 10b, which then has an internal thread.

[0067] The respective seal and guide sleeve 12 can protrude axially out of the hole 10 and thus out of the heat conduction body 8. It can include a polygonal end 121 there, for example. The seal and guide sleeve 12 itself includes a through hole 122.

[0068] The entire tip element 7, thus both the heat conduction body 8 and also the seal and guide sleeve 12, are axially penetrated by a closure needle 14, which moreover protrudes on both sides axially out of the tip element 7. The diameter of the closure needle 14 and the through hole 122 are matched so that the closure needle 14 is guided sealed in this hole.

[0069] In the region of the hole section 10a in front of the seal and guide sleeve 12, in contrast, the diameter can be selected so that a ring channel 13 is formed, preferably concentrically, around the closure needle 4, through which melt can be conducted up into the region of a tip 15 of the closure needle 14, which can protrude out of the heat conduction body 8.

[0070] At least one feed hole 131 aligned obliquely to the ring channel 14 can open into the ring channel 13, through which melt can be conducted out of the nozzle body 2 into the ring channel 13. Multiple such feed holes 131 per tip element 7 can also be provided.

[0071] The closure needle 14, which is displaceably guided, can protrude with a tip 15 out of the projection 11 in at least one operating position and can be moved forward and back using a drive means of the drive.

[0072] To achieve a good temperature control for the melt up to the article surfaces, the closure needles 14 are to be guided with their tip 15 up to the article surface (FIG. 6, FIGS. 7a-c). The plastic part to be injected or manufactured is injected into a mold W (also referred to as a molding tool hereinafter), of which, inter alia, a mold plate F is shown here, which includes a gate hole A, which is associated with a mold cavity FN. The gate hole A for the plastic is closable by the closure needle 14, the tip of which seals closed the gate hole A of the mold plate F in the closed position of FIG. 7a, so that plastic can no longer enter the mold. The closure needle 14 including tip 15 is retracted in FIG. 7b, so that melt can flow through the gate hole A. An ejection position for ejecting the plastic part is shown in FIG. 7c.

[0073] On its axial side — top in FIG. 1 — facing away from the pressure lid 3, the nozzle body 2 includes at least one melt entry opening into a melt channel 17 (FIG. 5 - not completely visible here), which can be divided into sub-channels 18, wherein the respective sub-channel 18 opens into one of the oblique holes 131, so that melt can be conducted through this hole 131 to the main channel 13 and the gate opening A to the mold cavity F.

[0074] To move the closure needle 14 using the drive means, the closure needle 14 includes on its end facing away from the tip 15, which protrudes out of the heat conduction body 8 and the seal and guide sleeve 12 at the end facing away from the tip 15, a coupling means 16 for coupling the closure needle 14 to the drive means. This coupling means 16 is embodied in a simple manner here as an angle, which extends approximately perpendicularly to the main extension direction of the closure needle 14.

[0075] The heat conduction body 8 of the tip element 7 forming the projection 11 at its outermost end protrudes radially outward beyond the circumferential edge of the nozzle body 2.

[0076] The tip elements 7 are designed in such a way that after insertion into the recesses 6, they are held laterally by sections of a radially outer circumferential wall 19, which can be penetrated in each case by the projection 11 and the seal sleeve 9 of the respective tip element 7, and by a rear buttress element 20 in one or more directions at least in the hot state.

[0077] The tip elements can be held laterally by further walls 21, 22 of the recesses 6. They are held on the top and bottom by the nozzle body 2 and by the pressure lid 3.

[0078] The seal sleeve 9 is furthermore supported on the mold tool W (see FIG. 4, FIG. 7c).

[0079] In the hot state, the respective tip element is supported in this way between the tool and the buttress element 20.

[0080] The tip elements 7 are insertable here in the cold state with some play into the recesses 6, for example, using a tool such as a screw 23 (FIG. 1c), which can be screwed into a threaded bore 24 of the tip elements and is releasable after the insertion. In the heated state, the tip elements are then seated securely in these recesses 6, wherein a solid seat of the heat conduction body 8 results between the buttress element 20 and the tool, on which the seal sleeve section 9 supports itself.

[0081] The buttress element 20 can be designed in such a way that it is insertable into the nozzle body 2 and removable therefrom. The buttress element 20 can in particular form a type of U-shaped bridge section 201 in each case per tip element 20. The buttress element can include a removal means for the removal. This can be designed as at least one threaded bore 31, into which a screw or the like can be screwed, using which the buttress element can then be removed (see FIG. 1b)). In this way, the buttress element can be easily replaced if necessary.

[0082] The respective bridge element 201 can, according to FIG. 1, overlap the tip element 7 from above from the direction of the pressure lid 3 — for example in the region of the respective polygonal end or in the region of a step or the like — and secures it after the placement of the pressure lid in the main extension direction HE and preferably perpendicularly thereto, for example, radially inward.

[0083] The bridge sections 201 required all around in this way for the circumferentially distributed tip elements 7 can be combined to form an encompassing element. According to FIGS. 1 to 7, this encompassing element including multiple bridge sections 201 is a ring, for example a circumferentially closed polygonal ring.

[0084] Each bridge section 201 then overlaps, for example, the respective polygonal end 121 of the respective needle seal and guide sleeve 12. Lower webs 202 of the bridge sections 201 can be held on a collar 25 (FIG. 4a) or in recesses 6 or the like on the nozzle body 2, in such a way that the buttress element 20 is supported securely there.

[0085] The tip elements 7 are installable well in this way, whereupon first these (FIG. 1c) and then the buttress element 20, the ring-like buttress element 20 here, is installed.

[0086] In this state, the tip elements 7 are then pressed by the pressure lid 3 in the direction of a main extension direction HE on the nozzle body 2, wherein a surface of the tip element 7 can support itself at least in the heated state of the hot runner nozzle on a web 202 of the buttress element 20. It is also provided here that the support of a tip element 7 is arranged on the buttress element 20 between the tip 15 of the closure needle 14 and the drive means 28, 29.

[0087] The coupling means 16 of the closure needles 14, for example, the angles, can engage in slotted guides 26 of a drive means, a rotatable drive ring 27 here, which is rotatable using a drive. For this purpose, the drive ring 27 can be coupled, for example, to a shaft 30 (FIG. 6), which is connected to a drive lever 29, which is movable via a motor or the like (otherwise not shown here), for example is pivotable in and opposite to the circumferential direction.

[0088] The drive ring 27 can be located radially inside the ring-like buttress element 20 in FIG. 1. By rotating the drive ring 27 with the slotted guides 26, which are aligned obliquely to the circumferential direction, the closure needles 14 can then easily be moved forward and back jointly to open or close the gate holes A.

[0089] The slotted guides 26 can be formed as straight oblong holes in which the angles engage or also in another shape.

[0090] This type of the drive is advantageous. However, another type of the drive can also be selected.

[0091] As shown in all figures, it can advantageously be provided that the support of a tip element 7 on the buttress element 20 is arranged between the tip 15 of the closure needle 14 and the drive means 28, 29.

[0092] In the exemplary embodiment of FIG. 8, the nozzle body 2 is formed cuboid. The pressure lid 3 can correspondingly be formed polygonal. It consists of two parts here. It can in turn be fixable on the nozzle body 2 using fastening means such as screws 5 (FIG. 8b).

[0093] Recesses 6 for tip elements 7 are in turn formed in the nozzle body 2. The tip elements 7 can be formed in the way of FIG. 3. The recesses 6 can also be provided like the recesses 6 of FIG. 1.

[0094] The drive means can be formed here not as a rotatable ring but as a linearly movable drive bar 28, which includes slotted guides (not visible here), in which the coupling means 16 engage, wherein the slotted guides can be designed so that the closure needles 14 are moved forward and back upon the linear movement of the drive bar 28.

[0095] The drive bar 28 can be movable by a drive otherwise not shown here.

[0096] The tip elements 7 can be oriented in the exemplary embodiment of FIG. 8, for example, in such a way that one or more of the tip elements 7, which face in opposite directions, are provided toward opposite sides of the nozzle body 2.

[0097] The recesses 6 can be designed similarly to the recesses of FIGS. 1 to 7. This means in each case there is a front wall 19 oriented toward the molding tool W and lateral walls 21, 22. The buttress element can in turn include one or more bridge sections 201. Two of the bridge sections are combined here by way of example to form a buttress element 20. This can be inserted into the nozzle body 2. It forms a buttress for the respective tip elements 7, which can in turn support themselves in the opposite direction on a tool.

[0098] Although the invention has been illustrated and described in detail by way of preferred embodiments, the invention is not limited by the examples disclosed, and other variations can be derived from these by the person skilled in the art without leaving the scope of the invention. It is therefore clear that there is a plurality of possible variations. It is also clear that embodiments stated by way of example are only really examples that are not to be seen as limiting the scope, application possibilities or configuration of the invention in any way. In fact, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete manner, wherein, with the knowledge of the disclosed inventive concept, the person skilled in the art is able to undertake various changes, for example, with regard to the functioning or arrangement of individual elements stated in an exemplary embodiment without leaving the scope of the invention, which is defined by the claims and their legal equivalents, such as further explanations in the description.

TABLE-US-00001 List of reference signs hot runner nozzle 1 nozzle body 2 pressure lid 3 nozzle holder 4 screws 5 recesses 6 tip elements 7 heat conduction body 8 seal sleeve section 9 hole 10 hole sections 10a, b, c projection 11 needle seal and guide sleeve 12 polygonal end 121 through hole 122 ring channel 13 feed hole 131 closure needle 14 tip 15 coupling means 16 melt channel 17 sub-channel 18 wall 19 buttress element 20 bridge sections 201 webs 202 wall 21, 22 screw 23 threaded hole 24 collar 25 slotted guide 26 drive ring 27 drive bar 28 drive lever 29 shaft 30 removal means 31 main extension direction HE gate hole A mold plate F mold tool W mold cavity FN lateral surface MF