Injection nozzle

Abstract

Injection nozzle (1) for injection molding of melted plastic material. The injection nozzle typically comprising a nozzle housing (2) enclosing a melt channel (3) for transporting during operation melted plastic material to a nozzle tip (4). Further the nozzle comprises a heating assembly (5) being attached in an assembled state to the nozzle housing (2) and being configured to heat during operation the nozzle housing (2). Said heating assembly (5) comprising a body (6) being arranged in thermal contact with the nozzle housing (2) a heating element (7) being arranged at the body (6) and in thermal contact with the nozzle housing (2) to transfer heat thereto and a temperature sensor element (8) being at least partially accommodated in an opening (9) of the body (6) and being arranged in thermal contact with the nozzle housing (2). The temperature sensor element (8) is thermally decoupled from the body (6) by an insulating element (10) to detect a temperature of the nozzle housing (2) in a distortion reduced manner.

Description

[0001] Injection nozzle

[0002] FIELD OF THE DISCLOSURE

[0003] The present disclosure relates to an injection nozzle according to the preamble of patent claims comprising a heating assembly and a heating assembly as such. The present disclosure further relates to an injection molding device comprising at least one injection nozzle and a method of operating the same.

[0004] BACKGROUND OF THE DISCLOSURE

[0005] The field of the disclosure pertains to injection nozzles designed for the injection molding of molten plastic materials. These injection nozzles typically consist of a nozzle body equipped with a melt channel, serving as a conduit for transporting the molten plastic material during operation. To ensure the necessary heating of the molten material in the melt channel during operation, a heating device is affixed to the nozzle body to heat the nozzle body. Within this domain of injection nozzles and specifically their heating devices, achieving the balance between efficient heating and accurate temperature sensing of the nozzle body has long been a point of contention. An injection nozzle heater's performance hinges on its ability to transfer heat to the nozzle body transporting melted plastic material while simultaneously monitoring the temperature of said nozzle body with high accuracy. However, an inherent challenge lies in the close proximity of the heating element and the temperature sensor within these heating devices. As they share a common space, the risk of thermal interference and inaccurate readings due to insufficient thermal separation looms large. The following sections will elucidate the problem at hand, considering existing solutions.

[0006] DE202008013626U1 published in 2009 in the name of Turk und Hillinger GmbH relates to a heating element having a tubular hollow body made of metal. The hollow body has one or more grooves with inserted or pressed tubular heaters in its outer and inner lateral surfaces. The tubular wall section is separated thermally from the tubular wall by two front sided notches and a sensor tip is fixed in a groove-like recess of a tubular wall section in a heat-transferring manner.

[0007] DE102008055640A1 published in 2010 in the name of Gunther Heisskanaltech- nik GmbH relates to a hot runner nozzle having a material tube, in which a flow channel is formed for a flowable material. A heater is provided for the flowable material, where a temperature sensor is arranged in the area of the heater. The temperature sensor is fixed at the material tube by a clip-like or ring-like fastening element. The fastening element surrounds the half of the outer periphery of the material tube.

[0008] DE102013013127A1 published in 2014 in the name of Otto Manner Innovation GmbH relates to a removable heating device for a hot runner nozzle containing an elongated heating unit which exhibits at least one longitudinal slot which does not extend as far in the longitudinal direction as the length of a substantially cylindrical heating unit and which enables an enlargement of the inner diameter of the heating unit by its open end. The heating device further has a channel disposed in the outer surface of the heating unit in which an electrical heating element is disposed. Furthermore, a heater / thermocouple assembly contains such a heating device and at least one thermocouple for detecting the temperature in the front end region of the hot runner nozzle.

[0009] SUMMARY OF THE DISCLOSURE

[0010] The present disclosure relates to an injection nozzle for injection molding of melted plastic material comprising a heating assembly addressing at least one limitation of the prior art.

[0011] In a variation the injection nozzle comprises a nozzle housing enclosing a melt channel for transporting, during operation, melted plastic material to a nozzle tip. A heating assembly being attached, in an assembled state, to the nozzle housing is configured to heat during operation the nozzle housing. Said heating assembly usually comprises a body being arranged in thermal contact with the nozzle housing and a heating element being arranged at the body and in thermal contact with the nozzle housing to transfer heat thereto. Typically a temperature sensor element being at least partially accommodated in an opening of the body and being arranged in thermal contact with the nozzle housing.

[0012] The injection nozzle according to the disclosure addresses an issue that has plagued the field for years - insufficient thermal separation between heating elements and temperature sensors. In a preferred variation the temperature sensor element is thermally decoupled from the body by an insulating element to detect a temperature of the nozzle housing in a distortion reduced manner. The heating assembly is thereby configured to control the temperature of the nozzle housing along its length, in particular in at the nozzle tip, close to a gate, crucial for quality control of the manufactured plastic parts and efficient heat distribution.

[0013] For good thermal insulation, the insulating element at least partially consists of a material having a lower thermal conductivity than the material of the body. Preferably the insulating element at least partially consists of a material having a coefficient of thermal conductivity between 0.02 W / mK and 10 W / mK (watt per meter-kelvin). Materials having such a coefficient of thermal conductivity are, but not limited to, certain ceramics or polyamides such as Vespel ®.

[0014] Depending on the design, the insulating element is arranged at least partially in the opening between the body and the temperature sensor element to thermally decouple the temperature sensor element from the body.

[0015] A sensor tip of the temperature sensor element is preferably accommodated in a coupling element thermally coupling during operation the sensor tip to the nozzle housing. This allows a detection of the temperature of the nozzle housing with reduced delay and increased precision. The coupling element at least partially consists of, but not limited to, a metal, preferably a copper alloy. In a preferred variation, the coupling element at least partially consists of a material having a similar or higher thermal conductivity than the material of the body, in particular the coupling element at least partially consists of a material having a coefficient of thermal conductivity between 15 W / mK and 300 W / mK, preferably 150 W / mK. If appropriate, the coupling element is in the assembled state at least partially encompassed by the insulating element and supported thereby with respect to the opening. Depending on the design, the insulating element comprises a receiving aperture for accommodating the coupling element at least partially therein. The receiving aperture may have an essentially circular cross-section, however other cross-section are possible, such as rectangular or polygonal.

[0016] Good results are possible, when the coupling element comprises a coupling surface contacting in the assembled state the nozzle housing and having a similar curvature as a contact surface of the body facing the nozzle housing. This allows an increased area of thermal contact between the coupling element and the nozzle body and ensures a good thermal transfer therebetween.

[0017] The quality of the temperature control of the injection nozzle depends, amongst others, on the (manufacturing) tolerances of the components involved. These tolerances, in case they are too large, can lead to problems in the thermal profile of the injection nozzle and furthermore to thermal problems during injection molding, which in turn can lead to quality problems in the process as well as in the injection molded plastic parts. A secure mechanical contact between the coupling element and the nozzle housing during operation is possible, when the coupling element is arranged retractable into the opening against a resetting force with respect to the insulating element, ensuring a continuous contact of the coupling element to the nozzle housing during operation. The coupling element is arranged slidable along the central axis of the opening (sliding direction) against a resetting force, to compensate certain tolerances. This provides during operation of the injection nozzle a mechanical contact between the coupling element and the nozzle housing, that is resilient to vibrations and / or manufacturing tolerances and / or thermal expansion of the components of the injection nozzle relative to each other.

[0018] Alternatively or in addition, the resetting force is provided by a spring element being formed as a separate element, such as a spring washer, or is integrally formed with the coupling element or is integrally formed with the insulating element or is incorporated into the sensor tip.

[0019] The coupling element may comprise an protrusion extending essentially parallel to the general extension of the body of the heating assembly, said protrusion resting in the assembled state against a support surface of the insulating element, in particular said protrusion is configured to exert at least part of the resetting force by elastic deformation when it is pressed against the support surface. In a preferred variation the protrusion is formed as a skirt or overhang at least partially encircling the coupling surface and being in the assembled state inset into a corresponding recess of the insulating element comprising the support surface.

[0020] Preferably, the insulating element is in the assembled state arranged in the opening fixed in position along the general extension of the opening by fastening means, in particular to provide support to the coupling element along the general extension of the opening. The fastening means can be formed by an undercut of the opening. In other variations the fastening means can be formed by an inner thread arranged in the opening and an outer thread arranged at the insulating element engaging in the assembled state with the inner thread of the opening. Preferably the insulating element comprises a contour for an assembly tool, such as internal hexagonal recesses for a hex key, however other contours are possible.

[0021] The fastening means are preferably adjustable in position along the general extension of the opening to adjust the position of the insulating element within the opening. This allows, depending on the design, to adjust the resetting force exerted on the coupling element in the assembled state.

[0022] To accommodate the sensor tip, the coupling element comprises receiving bore for friction and / or form fitting the sensor tip therein. The receiving bore can be machines or drilled in a (partially) assembled state of the heating assembly and / or the injection nozzle, while the coupling element and the encompassing insulating element are arranged in their operation position in the opening of the body. This ensures a precise fit of the sensor tip in the heating assembly. However the receiving bore can be drilled into the coupling element separately as well.

[0023] The sensor tip is inserted into the receiving bore of the coupling element in a direction essentially perpendicular to the sliding direction of the coupling element relative to the insulating element. This allows a clamping of the sensor tip in the assembled state relative to the body and or the insulating element.

[0024] Good results are possible, when the opening of the body is a through-bore providing outside access to the temperature sensor element and / or to the insulating element and / or to the coupling element. The outside access can be useful for visual inspection, in particular of the sensor tip and its position in the heating assembly. In case the nozzle housing has an essentially rectangular or polygonal, the body may be formed as a plate or the like. In case of a cylindrical nozzle housing, the body is preferably a sleeve configured to receive and thermally contact an injection nozzle in a central opening of the sleeve. The sleeve has an inner diameter, length in longitudinal direction, axis, inner surface, outer surface, and wall thickness. The body of the heating assembly is typically one piece, however multipiece constructions are also possible.

[0025] The body preferably comprises at least one longitudinal slot. If appropriate the slot does not extend the full length of the body. This slot has a width, an open end and a closed end, wherein adjacent to the closed end a bridge region of the body limits the enlargement of an inner diameter at one end of the body. However, the slot allows the body to expand the inner at the other end of the body at the open end of the slot. The longitudinal slot does extend relative to an axial length of the body at least 60%, preferably at least 80% or 90%. Depending on the design two or more slots can be foreseen, in particular having their open ends in alternating end regions of the body (in circumferential direction). Configurations with multiple longitudinal slots offer advantages, such as improved flexibility during tool-assisted removal, even if some slots are less accessible.

[0026] Depending on the design, the heating assembly with a sleeve body can be attached or removed from the nozzle housing by expanding the longitudinal slot, thereby widening the inner diameter of the central opening of the sleeve.

[0027] The heating element is typically an electrical heating element, however other types of heating elements are also possible, such as heat pipes (heat transfer via thermal medium). The body may comprise a groove to receive the heating element at least partially. If appropriate, the groove is arranged indented on an outside of the body (facing in the assembled state away from the nozzle housing). Preferably, the heating element is in thermal contact with a side wall of the groove to transfer heat to the body.

[0028] The groove preferably comprises windings or meanders, wherein the distance between said windings or meanders (and thus their density per region) effects the length of the heating element that is arranged in a certain region of the body. For good heating, the number of windings or meanders in a gate region (front end in longitudinal direction, close to gate of the nozzle body) is greater than in a central region of the body. The gate region typically refers to the front 10% or 20% of the axial length of the body close to the gate of the nozzle housing in the assembled state. The nozzle tip comprising the gate can be formed a separate element detachably arranged at the nozzle housing.

[0029] Depending on the design, the sensor tip is partially positioned between the nozzle housing and the inner surface of the body of the heating assembly, in particular of the sleeve. The body of the heating assembly preferably comprises an at least partially closed channel for accommodating the temperature sensor element. The channel can be arranged on the outside of the body, on the inside, or running therein (closed channel). The channel typically joins into the receiving bore of the coupling element (and the insulating element). Another aspect of the disclosure is directed to an injection molding device for injection molding of melted plastic material comprising at least one injection nozzle according to the disclosure. At least one temperature sensor element is during operation interconnected to a temperature controller. Said temperature controller being configured to control the heating element of the at least one injection nozzle based on a temperature of the nozzle housing determined from a signal of the temperature sensor element.

[0030] Another aspect of the disclosure is directed to method of operating an injection molding device comprising at least two injection nozzle, as described herein, in a thermally balanced manner. The method comprises the steps of determining by a temperature controller temperatures of the nozzle housings of the at least two injection nozzles based on signals received from the temperature sensor elements; and controlling by the temperature controller the heating elements of the at least two injection nozzles based on the determined temperatures, such that the nozzle housings are each at a pre-defined temperature, in particular at the same temperature.

[0031] The previously described embodiment of the method for operating the injection molding device disclose at the same time correspondingly designed embodiments of injection molding device and vice versa. The described embodiments of injection molding device and of the injection nozzle may serve to carry out the method according to the disclosure. It is to be understood that both the foregoing general description and the following detailed description present embodiments, and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments, and together with the description serve to explain the principles and operation of the concepts disclosed.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The herein described disclosure will be more fully understood from the detailed description given herein below and the accompanying drawings which should not be considered limiting to the disclosure described in the appended claims. The drawings are showing:

[0034] Fig. 1 a first variation of an injection nozzle according to the disclosure with a heating assembly detached from the nozzle housing;

[0035] Fig. 2 the first variation of Figure 1 , in an assembled state and in a partially sectioned view;

[0036] Fig. 3 a partially sectioned heating assembly of the first variation in an exploded view;

[0037] Fig. 4 a lateral view of the first variation of the injection nozzle;

[0038] Fig. 5 a section view of the nozzle of Figure 4; Fig. 6 a partially section and exploded view of a second variation of a heating assembly;

[0039] Fig. 7 a partially section and exploded view of a third variation of a heating assembly;

[0040] Fig. 8 a partially section and exploded view of a fourth variation of a heating assembly; and

[0041] Fig. 9 a schematic view of an injection molding device according to the disclosure.

[0042] DESCRIPTION OF THE EMBODIMENTS

[0043] 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.

[0044] In the shown first variation of Figure 1 the heating assembly 5 of the injection nozzle 1 is detached from the nozzle housing 2. At a front end of the nozzle housing 2, a nozzle tip 4 is arranged comprising gate 26, through which during operation melted plastic material is injected into a cavity (not shown) to form plastic parts. The nozzle housing 2 comprises on its outside an outer surface, which is in the assembled state in thermal contact with a contact surface 17 of a body 6 of the heating assembly 5. In the shown variation the body 6 is formed as a sleeve having a central opening 23 to receive the nozzle housing 2 therein. A heating element 7 is arranged at the body 6. The heating element 7 is in thermal contact with the nozzle housing 2, to transfer heat during operation to the nozzle housing 2, in order to heat the melted plastic material in the melt channel 3 of the nozzle housing 2. In particular, the heating element transfers heat to the nozzle tip 4 during operation. Depending on the design the heating element 7 transfers directly or indirectly heat to the nozzle housing 2. As shown in Figures 1 to 5, the heating element 7 transfers heat via the body 6 to the nozzle housing 2. This has the advantage, that the body 6 functions as a means for distributing the heat evenly to the nozzle housing 2.

[0045] To determine the temperature of the nozzle housing 2, the heating assembly 5 comprises a temperature sensor element 8 arranged at the body 6 in thermal contact with the nozzle housing 2. In the shown first variation, as visible in Figure 2, the body 6 of the heating assembly 5 comprises an opening 9 to at least partially accommodate the temperature sensor element 8. To thermally decouple the temperature sensor element 8 from the body 6, the heating assembly 5 comprises an insulating element 10. The insulating element 10 is arranged at least partially in the opening 9, separating the body 6 and the temperature sensor element 8. Thereby the temperature sensor element 8 is thermally decoupled from the body 6 and from the heating element 7. In particular, a sensor tip 11 of the temperature sensor element 8 is arranged in the opening 9 encompassed by the insulating element 10. The body 6 of the heating assembly 5 comprises four longitudinal slots 29, each slot 29 having an open end and a closed end arranged opposite to the open end. Each slot extends from its open end arranged in an end region of the body 6 to its closed end. The slots 29 have their open ends alternatingly at the opposing end regions of the body 6. Each slot 29 extends roughly 70% of an axial length of the body 6. In the shown variations of Figures 1 to 6, one slot 29 acts as part of a channel 28 of the body 6 for accommodating the temperature sensor element 8. The channel 28 joins into a receiving bore 20 for the sensor tip 11 , said receiving bore 20 extending in the assembled state through the insulating element 10 and the coupling element 12.

[0046] As illustrated in Figure 5, the insulating element 10 comprises a receiving aperture 27 for receiving add at least partially a coupling element 12. The coupling element 12 during operation couples the sensor tip 11 thermally to the nozzle housing 2.

[0047] As best visible in Figures 3 and 5, the coupling element 12 comprises a contact surface 16 facing the nozzle housing 2. The contact surface 16 has a curvature similar to the contact surface 17 of the body 6. This allows in the assembled state and essentially flush embedding of the contact surface 16 into contact surface 17. The coupling element 12 comprises in the shown variations a protrusion 13 formed as a skirt 15, which encircles the coupling surface 16. The protrusion 13 rests in the assembled state against a support surface 14 of the insulating element 10, wherein the support surface 14 is arranged in a recess 18 of the insulating element 10. Thereby also the protrusion 13 is separated by the insulating element 10 from the body 6 within the opening 9. The protrusion 13 is configured to exert a resetting force in the axial direction of the opening 9 when pressed against the support surface 14 by elastically deforming.

[0048] To accommodate the sensor tip 11 the coupling element 12 comprises a receiving bore 20 Into which the sensor tip 11 is friction or form fitted. Typically the receiving bore 20 is also present in the insulating element 10 which encompasses the coupling element 12, such that the temperature sensor element 8 is inserted through the insulating element 10 into the coupling element 12.

[0049] In the assemble state the insulating element 10 is fixed in position along the general extension of the opening 9 by fastening means 19. In the first variation the fasting means 19 comprises an inner thread arranged in the opening 9 (formed as a through bore 21 ) and an outer thread arranged at the insulating element 10. In the variation shown in Figure 6, the fasting means 19 comprises a separate nut with an outer thread for engaging with an inner thread of the opening 9. Here the insulating element 10 is pressed towards the central opening 23 by the nut 19, while keeping its orientation of the receiving bore 20. This allows to adjust in the assembled state the (resetting) force by which the coupling element 12 is pressed against the nozzle housing 2.

[0050] As indicated in Figure 7, a groove 30 is arranged on the outside of the body 6 to receive the heating element 7, which in this case is an electrical heating element 7 comprising a heating wire. The groove 30 comprises several windings around the central opening 23 of the sleeve 22, wherein the number of windings in a region of the nozzle tip 4 is higher compared to the number of windings in a center region of the sleeve 22. Figures 6 to 8 show different variations of heating assemblies 5 according to the disclosure. The variation of Figure 7 does not include a separate coupling element 12. In this third variation, the temperature sensor element 8 is routed on the outside of the body 6 without being received in a channel of the body 6. In the fourth variation, as shown in Figure 8, the fastening means 19 are formed as an undercut engaging with a corresponding projection of the insulating element 10, such that the undercut supports the insulating element 10 in axial direction of the opening 9. This way the insulating element 10 is able to provide support for the coupling element 12, when the resetting force is exerted.

[0051] In Figure 9 a schematic view of an injection molding device 24 is shown. The injection molding device 24 comprises at least two injection nozzles 1 according to the disclosure. The temperature sensor element 8 of each injection nozzle 1 is during operation interconnected to a temperature controller 25. Said temperature controller 25 is configured to control the heating element 7 of each nozzle 1 based on a temperature of the respective nozzle housing 2 determined from a signal of the respective temperature sensor element 8. The temperature controller 25 is in some variations configured to take into account additional sensor signals, form sensors such as cavity temperature and pressure sensors (not shown).

[0052] 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 scope of the disclosure. LIST OF DESIGNATIONS

[0053] 1 Injection nozzle 16 Coupling surface (coupling ele¬

[0054] 2 Nozzle housing ment)

[0055] 3 Melt channel 17 Contact surface (body of the

[0056] 4 Nozzle tip heating assembly)

[0057] 5 Heating assembly 18 Recess (insulating element)

[0058] 6 Body (heating assembly) 19 Fastening means

[0059] 7 Heating element 20 Receiving bore (coupling ele¬

[0060] 8 Temperature sensor element ment)

[0061] 9 Opening (body of the heating 21 Through-bore (opening - body) assembly) 22 Sleeve (body)

[0062] 10 Insulating element 23 Central opening (sleeve)

[0063] 11 Sensor tip (temperature sensor 24 Injection molding device element) 25 Temperature controller

[0064] 12 Coupling element 26 Gate (nozzle tip)

[0065] 13 Protrusion (coupling element) 27 Receiving aperture

[0066] 14 Support surface (insulating ele28 Channel (for temperature senment) sor element)

[0067] 15 Skirt (Protrusion - coupling ele29 Slot ment) 30 Groove

Claims

PATENT CLAIMS1. Injection nozzle (1 ) for injection molding of melted plastic material, the injection nozzle (1 ) comprising a. a nozzle housing (2) enclosing a melt channel (3) for transporting during operation melted plastic material to a nozzle tip (4); b. a heating assembly (5) being attached in an assembled state to the nozzle housing (2) and being configured to heat during operation the nozzle housing (2), said heating assembly (5) comprising: i. a body (6) being arranged in thermal contact with the nozzle housing (2); ii. a heating element (7) being arranged at the body (6) and in thermal contact with the nozzle housing (2) to transfer heat thereto; iii. a temperature sensor element (8) being at least partially accommodated in an opening (9) of the body (6) and being arranged in thermal contact with the nozzle housing (2); iv. wherein the temperature sensor element (8) is thermally decoupled from the body (6) by an insulating element (10) to detect a temperature of the nozzle housing (2) in a distortion reduced mannerv. wherein the opening (9) of the body (6) is a through-bore (21 ) providing outside access to the temperature sensor element(8) and / or to the insulating element (10).

2. The injection nozzle (1 ) according claim 1 , wherein the insulating element (10) is arranged at least partially in the opening (9) between the body (6) and the temperature sensor element (8) to thermally decouple the temperature sensor element (8) from the body (6).

3. The injection nozzle (1 ) according to at least one of the preceding claims, wherein a sensor tip (11 ) of the temperature sensor element (8) is accommodated in a coupling element (12) thermally coupling during operation the sensor tip (11 ) to the nozzle housing (2).

4. The injection nozzle (1 ) according to claim 3, wherein the coupling element (12) is in the assembled state at least partially encompassed by the insulating element (10) and supported thereby with respect to the opening (9).

5. The injection nozzle (1 ) according to at least one of the preceding claims 3 to 4, wherein the coupling element (12) comprises a coupling surface (16) contacting in the assembled state the nozzle housing (2) and having a similar curvature as a contact surface (17) of the body (6) facing the nozzle housing (2).

6. The injection nozzle (1 ) according to at least one of the preceding claims 3 to 5, wherein the coupling element (12) is arranged retractable into the opening (9) against a resetting force with respect to the insulating element(10) ensuring a contact of the coupling element (12) to the nozzle housing (2).

7. The injection nozzle (1 ) according to claim 6, wherein the coupling element(12) comprises an protrusion (13) extending essentially parallel to the general extension of the body (6) of the heating assembly (5), said protrusion(13) resting in the assembled state against a support surface (14) of the insulating element (10), in particular said protrusion (13) is configured to exert at least part of the resetting force when pressed against the support surface (14) by elastic deformation.

8. The injection nozzle (1 ) according to claim 7, wherein the protrusion (13) is formed as a skirt (15) at least partially encircling the coupling surface (16) and being in the assembled state inset into a corresponding recess (18) of the insulating element (10) comprising the support surface (14).

9. The injection nozzle (1 ) according to at least one of the preceding claims 2 to 8, wherein the insulating element (10) is in the assembled state arranged in the opening (9) fixed in position along the general extension of the opening (9) by fastening means (19), in particular to provide support to the coupling element (12) along the general extension of the opening (9).

10. The injection nozzle (1 ) according to claim 9, wherein the fastening means (19) are adjustable in position along the general extension of the opening (9) to adjust the position of the insulating element (10).11 . The injection nozzle (1 ) according to at least one of the preceding claims 3 to 10, wherein the coupling element comprises receiving bore (10) for friction and / or form fitting the sensor tip (11 ) therein.

12. The injection nozzle (1 ) according to at least one of the preceding claims, wherein the through-bore (21 ) provides outside access to the coupling element (12).

13. The injection nozzle (1 ) according to at least one of the preceding claims 1 to 12, wherein the insulating element (10) at least partially consists of a material having a lower thermal conductivity than the material of the body (6), in particular the insulating element (10) at least partially consists of a material having a coefficient of thermal conductivity between 0.02 W / mK and 10 W / mK.

14. The injection nozzle (1 ) according to at least one of the preceding claims 3 to 13, wherein the coupling element (12) at least partially consists of a material having a similar or higher thermal conductivity than the material of the body (6), in particular the coupling element (12) at least partially consists of a material having a coefficient of thermal conductivity between 15 W / mK and 300 W / mK, preferably 150 W / mK.

15. The injection nozzle (1 ) according to at least one of the preceding claims, wherein the body (6) is a sleeve (22) configured to receive and thermally contact an injection nozzle (1 ) in a central opening (23) of the sleeve (22).

16. Injection molding device (24) for injection molding of melted plastic material comprising at least one injection nozzle (1 ) according to at least one of the previous claims 1 to 15, wherein the temperature sensor element (8) is during operation interconnected to a temperature controller (25) being config- ured to control the heating element (7) based on a temperature of the nozzle housing (2) determined from a signal of the temperature sensor element (8).

17. Method of operating an injection molding device (24) comprising at least two injection nozzle (1 ) according to at least one of the previous claims 1 to 15 in a thermally balanced manner, the method comprising the steps of: a. determining by a temperature controller (25) temperatures of the nozzle housings (2) of the at least two injection nozzles (1 ) based on signals received from the temperature sensor elements (8); b. controlling by the temperature controller (25) the heating elements (7) of the at least two injection nozzles (1 ) based on the determined temperatures, such that the nozzle housings (2) are each at a predefined temperature, in particular at the same temperature.

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