Insert for an Injection-Moulding Nozzle and Injection-Moulding Nozzle Having Such an Insert

Abstract

An insert for an injection-moulding nozzle, having an insert body which has a rear end and a front end and in which at least one flow duct is formed between the rear end and the front end. In this case, the insert body has a first part for arranging the insert on or in the injection-moulding nozzle and a second part for arranging on or in a mould insert. The first part is manufactured from a first material and extends from the rear end of the insert body to a contact surface. The second part is manufactured from a material different from the first material and extends from the contact surface to the front end of the insert body. Furthermore, the first part and the second part are connected firmly together at and/or along the contact surface. Also disclosed, an injection-moulding nozzle can include the insert.

Claims

1. Insert for an injection-moulding nozzle, having an insert body which has a rear end and a front end and in which at least one flow duct is formed between the rear end and the front end, wherein the insert body has a first part for arranging the insert on or in the injection-moulding nozzle and a second part for arranging on or in a mould insert, characterized in that the first part is manufactured from a first material and extends from the rear end of the insert body to a contact surface, and in that the second part is manufactured from a material different from the first material and extends from the contact surface to the front end of the insert body, wherein the first part and the second part are connected together at and/or along the contact surface.

2. Insert according to claim 1, characterized in that the first part and the second part are connected together in a cohesive, form-fitting or frictional manner.

3. Insert according to claim 1, characterized in that the first part and the second part are connected cohesively together by means of welding.

4. Insert according to claim 1, characterized in that the first part and the second part are connected together by means of a mechanical connecting arrangement.

5. Insert according to claim 1, characterized in that the first material is a highly heat-conductive material and the second material is a wear-resistant material.

6. Insert according to claim 1, characterized in that the contact surface extends perpendicularly or obliquely to a longitudinal axis of the insert body.

7. Insert according to claim 1, characterized in that the insert body is formed in a rotationally symmetrical manner with respect to a longitudinal axis and has a first portion, a flange and a second portion.

8. Insert according to claim 1, characterized in that the first part of the insert forms a centring body for a valve needle of the injection-moulding nozzle.

9. Insert according to claim 8, characterized in that the second part forms a sealing seat for a valve needle of the injection-moulding nozzle.

10. Insert according to claim 1, characterized in that the second part is configured to form, with the front end, a portion of the wall of a mould impression.

11. Insert according to claim 1, characterized in that the second part is configured to form, around its outer circumference, at least one sealing surface with the mould insert, wherein the second part has at least one notch in the region of the sealing surface.

12. Injection-moulding nozzle for an injection mould, having an insert according to claim 1.

13. Injection-moulding nozzle according to claim 12, having a material tube in which at least one flow duct is formed which is connected in terms of flow to a mould cavity, formed by at least one mould insert, of the injection mould, characterized in that the insert is arrangeable at a mould-insert-side end of the material tube.

14. Injection-moulding nozzle according to claim 13, characterized in that the injection-moulding nozzle has a heat conducting sleeve, at the mould-insert-side end of which the insert is arrangeable.

15. Injection-moulding nozzle according to claim 14, characterized in that the insert is configured so as to be longitudinally displaceable with regard to the material tube, a nozzle mouthpiece or the heat conducting sleeve and the mould insert and, during operation of the injection-moulding nozzle, is clamped in place between the material tube and the mould insert, the nozzle mouthpiece and the mould insert or between the heat conducting sleeve and the mould insert.

16. Injection-moulding nozzle according to claim 14, characterized in that the first part is adapted in its form at least in part to the material tube, the nozzle mouthpiece or the heat conducting sleeve and the second portion is adapted in its form at least in part to the mould insert.

17. Injection-moulding nozzle according to one of claim 15, characterized in that the first part of the insert has a greater coefficient of thermal expansion than the material tube and/or the nozzle mouthpiece and/or the heat conducting sleeve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Further features, details and advantages of the invention can be gathered from the wording of the claims and from the following description of exemplary embodiments and the embodiments that are illustrated by way of example in the drawings, in which:

[0045] FIG. 1 shows a schematic longitudinal section through a first embodiment of an insert according to the invention;

[0046] FIG. 2 shows a schematic longitudinal section through another embodiment of an insert according to the invention; and

[0047] FIG. 3 shows an enlarged detail of a schematic longitudinal section through yet another embodiment of an insert according to the invention.

DETAILED DESCRIPTION

[0048] In the processing of thermosets and elastomers, where the plastics material cures under the influence of temperature, instead of hot runner systems, cold runner systems are accordingly used. Therefore, where hot runner systems are described in the following text, cold runner systems are also always meant, mutatis mutandis, depending on the application.

[0049] FIGS. 1 and 2 each show a longitudinal section through an insert 10 for an injection-moulding nozzle (not illustrated). The insert 10 is formed in each case by a corresponding insert body 20. In this case, the insert body 20 has a first part 28 having a rear end 22 which can be arranged on an injection-moulding nozzle, for example by being inserted into the injection-moulding nozzle or by being placed on the injection-moulding nozzle. Furthermore, the insert body 20 has a second part 30 having a front end 24 which is adapted to be inserted into a mould insert. Preferably, the second part is embodied in this case such that it forms at its end a portion of the mould impression wall of an injection mould.

[0050] The first part 28 of the insert body 20 is in this case connected in a cohesive or form-fitting manner to the second part 30 of the insert body 20 along a contact surface 32. A cohesive connection between the first part 28 of the insert body 20 and the second part 30 of the insert body 20 can be established for example by welding the two parts along the contact surface 32, in particular by diffusion welding. A form-fitting connection could be ensured for example by using a corresponding mechanical arrangement, for example a screw thread, a press fit or a bayonet closure. The first part 28 of the insert body 20 can in this case consist for example of a material which has high thermal conductivity, while the second part 30 of the insert body 20 can consist of a material which has high wear resistance. For example, the second part 30 of the insert body 20 can be made of tool steel.

[0051] The insert 10 illustrated in FIG. 1 is embodied so as to be rotationally symmetrical about a longitudinal axis L of the insert 10 and has a first neck portion 34 which is arranged at the rear end 22, and a second neck portion 38 which is arranged at the front end 24. In this case, the first neck portion 34 is embodied such that the insert 10 can be inserted by way of the first neck portion 34 into the material tube, the nozzle mouthpiece or the heat conducting sleeve of an injection-moulding nozzle. At the same time, the second neck portion 38 is adapted such that it can be inserted into the mould insert of an injection mould. Provided between the first neck portion 34 and the second neck portion 38 is a flange 36, which can be used for example as a supporting flange. In this case, the underside of the flange 36 rests on the mould insert of an injection mould, while the top side of the flange bears against the material tube, the nozzle mouthpiece or the heat conducting sleeve of an injection-moulding nozzle.

[0052] As illustrated in FIG. 1, the contact surface 32 extends through the flange 36 in the radial direction perpendicularly to the longitudinal axis L of the insert 10. Thus, the first neck portion consists exclusively of the first material, while the second neck portion 38 consists exclusively of the second material. By contrast, the flange 36 is divided in two in terms of its material composition. In an alternative embodiment which is illustrated in FIG. 2, the contact surface 32 extends beneath the flange 36. Furthermore, in the embodiment illustrated here, the contact surface extends obliquely to the longitudinal axis L of the insert 10, such that in the case of a rotationally symmetrical insert 10, a conical profile of the contact surface 32 is produced. In this case, the flange 36 and the first neck portion 34 accordingly consist of the first material, while the second neck portion 38 is made of the second material.

[0053] Between the rear end 22 and the front end 24, a flow duct 26 extends through the insert body 20, which is configured to deliver a plastic melt to a mould insert. The flow duct 26 is in this case embodied so as to taper conically in the direction of the front end 24 in the region of the first part 28 of the insert 10. As a result of the conical profile of the flow duct 26, when the insert is used in a needle valve nozzle, a centring effect is achieved for the shut-off part of the needle.

[0054] FIG. 3 shows a further longitudinal section through an insert 10. In the embodiment illustrated in FIG. 3, the insert 10 has been fitted into a corresponding opening in a mould insert 40 of an injection mould, such that the front end 24 of the insert forms a portion of the wall of a mould impression located therebeneath. As is further apparent in FIG. 3, the second portion 38 has been inserted into a corresponding recess in the mould insert 40 while the flange 36 is supported on the top side of the mould insert 40. As a result of the size of the recess in the mould insert 40 being adapted to the circumference of the insert 10 in the region of the second portion 38, a sealing surface 42 can be created between the insert 10 and the mould insert 40, as is illustrated in FIG. 3. As a result of the sealing surface 42, during an injection-moulding operation, a reverse flow of the injected plastics material into the region between the insert 10 and the mould insert 40 can be avoided.

[0055] In this case, in accordance with the embodiment illustrated in FIG. 3, a notch 44 is provided in the second portion 38 of the insert 10. By way of the notch 44, an air gap is created between the mould insert 40 and the second portion 38 of the insert 10, said air gap allowing at least partial thermal insulation of the insert 10 with respect to the mould insert 40 in the region of the second portion 38. Thus, heat transmission between the mould insert 40 and the insert 10 and thus also between the mould insert 40 and the plastics melt located in the flow duct 26 could be avoided as a result of the notch 44 and the resulting gap between the insert 10 and the mould insert 40.

[0056] It can be seen that an insert 10 for the lower end of an injection-moulding nozzle has an insert body 20 which has a rear end 22 and a front end 24 and in which at least one flow duct 26 is formed between the rear end 22 and the front end 24. The insert body 20 has in this case a first part 28 for arranging the insert on or in the injection-moulding nozzle and a second part 30 for arranging on or in a mould insert 40. According to the invention, the first part 28 is manufactured from a first material and extends from the rear end 22 of the insert body 20 to a contact surface 32. The second part 30 is manufactured from a material different from the first material and extends from the contact surface 32 to the front end 24 of the insert body 20. The first part 28 and the second part 30 are furthermore connected firmly together at and/or along the contact surface 32.

[0057] All of the features and advantages that are disclosed by the claims, the description and the drawing, including structural design details, spatial arrangements and method steps, may be essential to the invention both on their own and in a wide variety of combinations.

ADDITIONAL DESCRIPTION

[0058] With reference to the figures, further embodiments are discussed:

[0059] Embodiment 1 is an insert 10 for an injection-moulding nozzle, having an insert body 20 which has a rear end 22 and a front end 24 and in which at least one flow duct 26 is formed between the rear end 22 and the front end 24, wherein the insert body 20 has a first part 28 for arranging the insert on or in the injection-moulding nozzle and a second part 30 for arranging on or in a mould insert 40, characterized in that the first part 28 is manufactured from a first material and extends from the rear end 22 of the insert body 20 to a contact surface 32, and in that the second part 30 is manufactured from a material different from the first material and extends from the contact surface 32 to the front end 24 of the insert body 20, wherein the first part 28 and the second part 30 are connected together at and/or along the contact surface 32.

[0060] Embodiment 2 is an insert according to Embodiment 1, characterized in that the first part 28 and the second part 30 are connected together in a cohesive, form-fitting or frictional manner.

[0061] Embodiment 3 is an insert according to any of Embodiments 1 to 2, characterized in that the first part 28 and the second part 30 are connected cohesively together by means of welding.

[0062] Embodiment 4 is an insert according to any of Embodiments 1 to 2, characterized in that the first part 28 and the second part 30 are connected together by means of a mechanical connecting arrangement.

[0063] Embodiment 5 is an insert according to any of Embodiments 1 to 4, characterized in that the first material is a highly heat-conductive material and the second material is a wear-resistant material.

[0064] Embodiment 6 is an insert according to any of Embodiments 1 to 5, characterized in that the contact surface 32 extends perpendicularly or obliquely to the longitudinal axis L of the insert body 20.

[0065] Embodiment 7 is an insert according to any of Embodiments 1 to 6, characterized in that the insert body 20 is formed in a rotationally symmetrical manner with respect to the longitudinal axis L and has a first portion 34, a flange 36 and a second portion 38.

[0066] Embodiment 8 is an insert according to any of Embodiments 1 to 7, characterized in that the first part 28 of the insert 10 forms a centring body for a valve needle of the injection-moulding nozzle.

[0067] Embodiment 9 is an insert according to any of Embodiments 1 to 8, characterized in that the second part forms a sealing seat for a valve needle of the injection-moulding nozzle.

[0068] Embodiment 10 is an insert according to any of Embodiments 1 to 9, characterized in that the second part 30 is configured to form, with the front end 24, a portion of the wall of a mould impression.

[0069] Embodiment 11 is an insert according to any of Embodiments 1 to 10, characterized in that the second part 30 is configured to form, around its outer circumference, at least one sealing surface 42 with the mould insert 40, wherein the second part 30 has at least one notch 44 in the region of the sealing surface 42.

[0070] Embodiment 12 is an injection-moulding nozzle for an injection mould, having an insert 10 according to any of Embodiments 1 to 11.

[0071] Embodiment 13 is an injection-moulding nozzle according to Embodiment 12, having a material tube in which at least one flow duct is formed which is connected in terms of flow to a mould cavity, formed by at least one mould insert 40, of the injection mould, characterized in that the insert 10 is arrangeable at the mould-insert-side end of the material tube.

[0072] Embodiment 14 is an injection-moulding nozzle according to any of Embodiments 12 to 13, characterized in that the injection-moulding nozzle has a heat conducting sleeve, at the mould-insert-side end of which the insert 10 is arrangeable.

[0073] Embodiment 15 is an injection-moulding nozzle according to any of Embodiments 12 to 14, characterized in that the insert 10 is configured so as to be longitudinally displaceable with regard to the material tube, the nozzle mouthpiece or the heat conducting sleeve and the mould insert 40 and, during operation of the injection-moulding nozzle, is clamped in place between the material tube and the mould insert 40, the nozzle mouthpiece and the mould insert 40 or between the heat conducting sleeve and the mould insert 40.

[0074] Embodiment 16 is an injection-moulding nozzle according to any of Embodiments 12 to 15, characterized in that the first part is adapted in its form at least in part to the material tube, the nozzle mouthpiece or the heat conducting sleeve and the second portion is adapted in its form at least in part to the mould insert 40.

[0075] Embodiment 17 is an injection-moulding nozzle according to any of Embodiments 12 to 16, characterized in that the first part 28 of the insert 10 has a greater coefficient of thermal expansion than the material tube and/or the nozzle mouthpiece and/or the heat conducting sleeve.

LIST OF REFERENCE SIGNS

[0076] L Longitudinal axis [0077] 10 Insert [0078] 20 Insert body [0079] 22 Rear end [0080] 24 Front end [0081] 26 Flow duct [0082] 28 First part [0083] 30 Second part [0084] 32 Contact surface [0085] 34 First neck portion [0086] 36 Flange [0087] 38 Second neck portion [0088] 40 Mould insert [0089] 42 Sealing surface [0090] 44 Notch