Hot runner assembly and injection mold comprising the same

Abstract

The present disclosure is directed to an injection mold and a thereto related hot runner assembly comprising a manifold and at least one nozzle assembly. The at least one nozzle assembly comprises a valve opening, and a valve needle arranged displaceable by an actuator between a closed position and an open position. The injection mold further comprises a processing unit. The processing unit is interconnected to the at least one sensor and to an actuator of at least one nozzle assembly. The processing unit is configured for adjusting and / or setting the position of the valve needle by the actuator based on a signal received from the sensor.

Description

HOT RUNNER ASSEMBLY AND INJECTION MOLD COMPRISING THE SAMECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to German Patent Application Nos. 102024111872.5, filed April 26, 2024; 102024125563.3 filed September 6, 2024, and 102024127916.8 filed September 26. 2024, the contents of each are incorporated by reference herein in their entirety.FIELD OF THE DISCLOSURE

[0002] The present disclosure relates to hot runner assemblies and injection molds comprising such hot runner assemblies. The disclosure in particular relates to hot runner assemblies comprising at least one processing unit for adjusting and / or setting the position of a valve needle of a nozzle assembly.BACKGROUND OF THE DISCLOSURE

[0003] Over the years, numerous advancements have been made in hot runner systems comprising one or more injection nozzles and cavity sensors, which provide enhanced productivity and capabilities for molders. The manner in which a mold cavity fills has a significant impact on the quality of the injection-molded part. Even minor alterations to the timing, temperature and pressure as the molten plastic material (melt) fills the cavity can influence the dimensions, aesthetics and functional strength of the part. Cavity sensors have played a crucial role in monitoring the injection molding process, providing valuable data on timing, temperature, and pressure as the melted plastic material fills the mold cavity. As an example, for larger injection-molded part, often more than one injection nozzle is used to inject melted plastic material into the cavity in which the injection-molded part is formed. Typically valve gated nozzles are installed to fill the cavity in a cascade manner (i.e., sequentially) to achieve high part quality. The implementation of automatic cascade control can be achieved through the utilization of sensors positioned within the cavity. Known approaches typically involve the arrangement of cavity sensors in the mold cavity in proximity to the respective injectionpoint (i.e. , next to the gate of the respective injection nozzle). However, this approach necessitates additional efforts on the part of the mold maker to install sensors in the cavity of the mold. This is only possible by drilling holes into the mold for arranging sensors at relevant positions. Furthermore the sensors must be integrated into the wall of the cavity to prevent optical damages to the part to be produced.

[0004] In arrangements known from the prior art the control of the injection process which is often done through an external device which is arranged next to the machine requiring additional space and auxiliary equipment.

[0005] US2014210119A1 published in 2014 in the name of Synventive Molding Solutions relates to an apparatus for performing an injection molding cycle, comprising: a manifold routing injection fluid to two or more gates, an actuator associated with each gate, each gate having a downstream sensor that senses a selected condition of the injection fluid material, a controller, the downstream sensors establishing a standard elapsed time, the controller including instructions that compares the standard elapsed time with a calculated amount of elapsed time associated with each of the gates and that adjust the velocity' or position of each of the actuators.

[0006] US2021078226A1 published in 2021 in the name of Synventive Molding Solutions relates to an injection molding system comprising: a first selected valve, one or more downstream valves, delivenng a fluid to a mold cavity, at least one fluid property sensor, each valve associated with a position sensor that detects opening of a gate at an actual open gate time to the controller, the controller automatically adjusting time of instruction to open the gates on a subsequent injection cycle by an adjustment time equal to any delay in time between a predetermined open gate target time and an actual open gate time, wherein the system forms a first one or more parts or objects, the user inspecting or measuring the first one or more parts or objects and manually adjusts the predetermined open gate target time.

[0007] EP1761375B1 has been first published in March 2007 on behalf of Priamus System Technologies AG. It relates to a method for filling at least one cavity of a tool for producing a preform from a melted mass, specifically a cavity of a tool in aninjection molding machine. The melted mass being introduced into the cavity under pressure from a plurality of nozzles. According to the method, a sensor is associated with at least one nozzle, the sensor determining the flow of melted mass in the cavity. The filling process through the nozzles is automatically coordinated on the basis of the signals of the sensor.SUMMARY OF THE DISCLOSURE

[0008] The present disclosure is directed to an injection mold and a thereto related hot runner assembly comprising a manifold and at least one nozzle assembly, usually two or more, which in combination enable significant advantages over the prior art explained in more detail hereinafter.

[0009] Operating inj ection molds known from the prior art with two or more valve gated nozzles is often very complicated, especially when multiple nozzles are present for filling of one cavity for forming larger parts which long flow paths. In such cases, additional sensors are usually installed for monitoring (and controlling) melt flow in real time, however adding these sensors requires significant effort and adoption. Typically, thermocouples (temperature sensors) are integrated in the mold, in particular into a wall of the cavity. The thermocouples are often connected to a separate actuation controller, which controls valve needle actuators to actuate the needle of the valve gates nozzles. Depending on the design, setting of the delays for opening / closing of the gates of the nozzles is done manually during a manual calibration phase done by the operator. These actuation controllers are typically complex, expensive and bulky' separate devices, which are during operation arranged next to the injection molding machine.

[0010] The presently disclosed hot runner assembly and injection mold comprising the same offer significant improvements over the prior art. In a preferred variation, the injection mold comprises a first mold half and a second mold half interacting with each other during operation along a separation plane between an open and a closed position. During operation, the injection mold is arranged in an injection molding machine which often has its own processing unit which until now often was dominating the process. In the present disclosure, the first and the second mold half areforming in the closed position at least one cavity therebetween. The injection mold further comprises a hot runner assembly arranged at the first mold half. The hot runner assembly comprises a manifold and at least one thereto interconnected nozzle assembly to inject during operation molten plastic material from a melt channel into at least one thereto interconnected cavity of the injection mold. Depending on the field of application, more than nozzle assembly can be connected to the same or different cavity. The at least one nozzle assembly comprises a valve opening and a valve needle arranged displaceable by an actuator between a closed position and open position. In the closed position the valve needle closes the valve opening and thereby blocks the passage of molten plastic material from the melt channel through the valve opening, and in the open position the valve needle allows passage of molten plastic material from the melt channel through the valve opening into the cavity to form a part corresponding to the shape of the cavity. The injection mold comprises at least one sensor interconnected to the cavity and / or the melt channel for providing a signal related to the molten plastic material injected into the cavity. The injection mold further comprises a processing unit. The processing unit is interconnected to the at least one sensor and to an actuator of at least one nozzle assembly. The processing unit is preferably configured for adjusting and / or setting the position of the valve needle by the actuator based on a signal received from the sensor.

[0011] The processing unit is in a preferred variation arranged in a housing attached to and / or incorporated in the first mold half and thereby usually forms part of the injection mold.

[0012] In some variations, the processing unit can be arranged in two housings, at least one being attached to and / or incorporated in the first mold half and at least one being separate from the injection mold or separatable from the injection mold connected thereto by a communication network. In this case the injection mold comprises a communication interface (e.g. a RJ45 connector or a wireless connector) for exchanging data with the processing unit, preferably via a data bus.

[0013] Depending on the design and the field of usage, the processing unit is arranged in a housing attached to the first mold half. Alternatively the housing of the processing unit can be incorporated into the first mold half.

[0014] If appropriate, the housing of the processing unit is attached to a mold frame of the first mold half and / or the manifold and / or the nozzle assembly and / or the actuator. This offers the advantage that the hot runner assembly and / or the injection mold can be preinstalled, wired and calibrated which significantly simplifies the operation and maintenance. Interaction with the injection molding machine (IMM) preferably occurs by an IMM interface provided for this purpose (e.g. Euromap 77, Euromap 67). The housing of the processing unit can be a connector box by which the processing unit is inter connectable to an injection molding machine by at least one connector arrangement comprising a first connector and a second connector interconnected to each other during operation (e.g. a Harting connector).

[0015] In some variations, the processing unit is arranged at the nozzle assembly, in particular at a housing of the actuator. Depending on the implementation, when more than one nozzle assembly is present, a processing unit per nozzle assembly can be foreseen. In this configuration, the processing units can be connected to each other via a bus connection to communicate amongst each other. If appropriate, one processing unit includes the IMM interface to receive signals from the injection molding machine, this processing unit may act as a master processing unit. This implementation has the advantage that individual wiring between each sensor, the nozzle assembly respectively, and the one (central) processing unit becomes obsolete, as nozzle assemblies can be communicatively connected in a daisy-chain manner.

[0016] Depending on the design and the field of usage, the actuator can be a pneumatic actuator or hydraulic actuator and actuated by an electric valve interconnected to processing unit. A reduction in complexity can be achieved when the electric valve is operatable with a similar voltage as the processing unit. Alternatively, or in addition, the electric valve and the processing unit are both AC-drivable (alternating cunent). Electric valves operatable with AC compared to traditional DC operated valves offer the advantage that the electronics required to drive them (converting of 230V or 110V AC mains power to lower voltage DC) become mostly obsolete. This allows a higher degree of integration of the actuation control into the injection mold, and / or the hot runner assembly, respectively. During operation of the injection mold in an injection moldingmachine, only a hydraulic or pneumatic source and IMM interface (to receive a “cycle begin” signal (EUROMAP 77)) need to be connected to the injection mold. The opening and closing of the valve opening can be controlled internally by the processing unit without the need for a separate actuation controller.

[0017] Alternatively, or in addition, to the at least one sensor the processing unit may be interconnectable to the injection molding machine interconnected during operation to the cavity for supplying the molten plastic material injected into the cavity, wherein the processing unit is configured to receive a signal related to the molten plastic material injected into the cavity from the injection molding machine. This allows to omit (or complement) the at least one sensor, while the processing unit controls the needle position based on signals received from the injection machine only. In an exemplary implementation of this, the processing unit is configured to control the needle positions to sequentially open the valve openings based on predetermined time intervals with the injection molding machine providing a “cycle begin” signal. The signal received from the injection molding machine may comprise information indicative of a position of a screw of an extruder of the injection molding machine and / or of the volume of the material provided thereby.

[0018] Good performance is possible, when the electric valve and the processing unit are operatable by a common power supply. In a particularly preferred variation, an external temperature controller can act as the common power supply for the valves and the processing unit.

[0019] Preferably the processing unit is configured to receive from the injection molding machine via the IMM interface an “emergency stop” signal (EUROMAP 67). In this case the processing unit is configured to control the actuator to set the valve needle(s) to the closed position. Implementing the procedure for the injection mold, the hot runner respectively, to engage a safe state integrated into the injection mold increases the safety. This is in contrast to an injection mold depending on an external actuation controller, where in between the injection mold and the external actuation controller additional failures can cause prevention or delay of the safe state after receipt of an “emergency stop” signal.

[0020] In particular, the present disclosure relates to a hot runner assembly specifically designed to enhance the operational efficiency and quality control in injection molding processes. In a variation, this technology integrates force sensors behind the valves needle of a nozzle assembly to indirectly measure pressure within the cavity, thus enabling real-time detection and control of the injection process. Alternatively, or in addition, a temperature sensor can be arranged at the nozzle assembly, preferably in a tip of the valve needle, providing a signal indicative of a melt front reaching or passing by the valve needle tip. Key aspects of the disclosure include a sophisticated electronic device in the form of a processing unit that may capture and process force / pressure and or temperature and / or valve needle position data in real time.

[0021] For an easy use, the processing unit may comprise a HMI interface for connecting a HMI (human machine interface), such as a display. The processing unit is preferably configured to display a graphical user interface on the HMI once connected to the processing unit via the HMI interface. This can be implemented by the processing unit being configured to run during operation a web server. In some variations the display forms part of the processing unit. If appropriate the processing unit is configured to receive instructions via the HMI interface and / or via the IMM interface to adjust its operation, in particular regarding the adjustment and / or setting of the valve needle positions. Alternatively, or in addition, the processing unit may facilitate dynamic adjustment of needle positions, by operation of electric valves, in particular solenoid valves, however other kinds of valves may be applicable. Additionally, a seamless safety interface with the Injection molding machine ensures optimal operational conditions by providing essential input / output signals. In difference to the prior art, the hot runner assembly’s capabilities may be extended to performing comprehensive data analysis and closed-loop control directly on the mold, thereby eliminating or reducing the dependence on external systems. This integrated approach not only simplifies the setup but also significantly reduces the potential for failures and operational errors. In particular the previously dominant injection molding machine may to a certain extend step down in its control function (reduced to initiate cycles and provide melt).

[0022] Further enhancing its application, the hot runner assembly according to the disclosure may be designed for various use cases that demand minimal setup time, automatic compensation for process fluctuations, and the ability to handle critical materials or unexpected changes in material properties. The design may uniquely support operation with minimal dependence on the injection molding machine. Preferably the hot runner assembly is operatable in a minimal configuration together with standardized connections, to the injection molding machine (“start cycle” signal) and a pneumatic or hydraulic source to actuate the actuators. This reduced dependency on external devices provides significant benefits in terms of cost, risk reduction, and operational flexibility.

[0023] This disclosure represents a notable advancement over prior art as it may allow integrating real-time mass flow analysis within the cavity, thus enabling dynamic actuation of valve needles based on actual conditions rather than predetermined static signals. This holistic approach ensures enhanced performance, quality control, and adaptability in modem injection molding operations.

[0024] In particular the hot runner assembly presents several practical use cases aimed at improving efficiency and reducing the complexities traditionally associated with injection molding processes. In particular, it offers streamlined installation and setup, wherein the hot runner assembly can be designed to automatically configure the cascade of a mold, significantly reducing the time required for installation and setup. This feature is particularly beneficial for customers seeking to minimize initial preparation times.

[0025] Furthermore, it is possible to compensate for process fluctuations, in that the integrated processing unit and the hot runner assembly may allow automatically compensating for process fluctuations. This allows for autonomous molding operations that are independent of manual adjustments, thereby ensuring consistent quality and performance. In addition, the technology' may support processes that are purely based on injection mold configurations (such as cavity geometry ) and can be easily transferred between different injection molds. This flexibility’ is beneficial for operations requiring frequent changes in injection mold designs or for those utilizing multiple molds.

[0026] Another beneficial aspect is the potential for the handling of materials, traditionally considered difficult to process due to variations of the material during processing. Examples are post-consumer recycled (PCR) or post-industrial recycled (PIR) resins, which typically require significant manual efforts to stabilize. The hot runner assembly's ability to react autonomously to unforeseen changes (e.g. in material viscosity) enhances its utility in handling complex materials.

[0027] A further positive aspect is the possibility for determination of the volumetric filling status in the mold. This can be achieved in that based on volumetric fill detection through melt front detection with a temperature sensor or based on identification of volumetric filling through analysis of pressure curves (projected force measured behind the needle). In addition, it can be possible to derivate the cascade switching times depending on the filling status in that the melt front detection allows for triggering of valve gate opening and closing times. This also accounts for valve needle position between open and closed. Furthermore, it becomes possible to easily detect deviations (too late I too early) and adjust them or correction in the subsequent cycle in an adaptive manner, in particular by monitoring of the condition of the melt, the manifold and the cavity based on the timing versus an identifier (e.g. start injection from IMM, mold closing signal, etc ).

[0028] Identification of outliers respectively changes outside of the scope and process limits can also be implemented. Furthermore, it becomes possible to protect the injection mold and the hot runner via monitoring of critical states (e.g. hot runner with residual pressure, but no needle opening or strongly delayed): Pressure level or fill status monitoring based on values measured at the tip or the end of the needle.

[0029] A further aspect is quality monitoring via detection of the melt position, preferably by viscosity' monitoring as melt front detection correlates with viscosity' as long as machine parameters remain unchanged from cycle to cycle (adaptive monitoring). If appropriate, the arrangement offers a self-sufficient layout that enables operation with minimal machine and operator requirements (only basic interfaces and connections required).

[0030] Furthermore it is possible to interconnect the processing unit to a user interface in either a temperature or machine controller or to a separate standalone user interface.

[0031] Another aspect of the disclosure relates to a hot runner assembly for an injection mold. The hot runner assembly comprises typically at least one, preferably two or more, nozzle assemblies according to the disclosure attached to a common manifold distributing during operation melted plastic material into the respective melt channels.

[0032] Preferably the hot runner assembly comprises a manifold and at least one thereto interconnected nozzle assembly to inject during operation molten plastic material from a melt channel into at least one thereto interconnected cavity of the injection mold. Depending on the field of application, more than nozzle assembly can be connected to the same cavity’. The at least one nozzle assembly comprises a valve opening and a valve needle arranged displaceable by an actuator between a closed position, in which the valve needle closes the valve opening and thereby blocks the passage of molten plastic material from the melt channel through the valve opening, and an open position in which the valve needle allows passage of molten plastic material from the melt channel through the valve opening into the cavity to form a part corresponding to the shape of the cavity. The injection mold comprises at least one sensor interconnected to the cavity and / or the melt channel for providing a signal related to the molten plastic material injected into the cavity. The injection mold further comprises a processing unit. The processing unit is interconnected to the at least one sensor and to an actuator of at least one nozzle assembly. It is configured for adjusting and / or setting the position of the valve needle by the actuator based on a signal received from the sensor.

[0033] In another preferred variation, the hot runner assembly comprises a manifold and at least one thereto interconnected nozzle assembly to inject during operation molten plastic material from a melt channel into at least one thereto interconnected cavity of the injection mold. Depending on the field of application, more than nozzle assembly can be connected to the same cavity. The at least one nozzle assembly comprises a valve opening and a valve needle arranged displaceable by an actuator between a closed position, in which the valve needle closes the valve openingand thereby blocks the passage of molten plastic material from the melt channel through the valve opening, and an open position in which the valve needle allows passage of molten plastic material from the melt channel through the valve opening into the cavity to form a part corresponding to the shape of the cavity. The injection mold further comprises a processing unit interconnectable to at least one sensor interconnected to the cavity for providing a signal related to the molten plastic material injected into the cavity. Alternatively or in addition the processing unit is interconnectable to an injection molding machine supplying during operation molten plastic material injected into the cavity. The processing unit is interconnected to an actuator of at least one nozzle assembly and configured for adjusting and / or setting the position of the valve needle by the actuator based on a signal received from the sensor and / or from the injection molding machine. The processing unit is in particular to the actuator of the at least one nozzle assembly and configured for adjusting and / or setting the position of the valve needle via said actuator based on a signal received from the sensor and / or based on a signal received from the injection molding machine.

[0034] Such hot runner assemblies can be installed in an injection mold without requiring the installation of additional sensors in the cavity. As a result, no additional wiring for cavity sensors is required leading to a reduction cost to the mold maker and reduced risk of damage to (cavity) sensors. A hot runner assembly according to the disclosure can be considered to be “plug and play'’, since the hot runner assembly can be inserted into a prepared injection mold without additionally installing sensors in the cavity (or cavities), while providing the same level of process control (i.e. cascade opening of nozzles).

[0035] Preferably the hot runner assembly comprises a junction box being connected to the sensors of the at least one nozzle assembly for receiving signals therefrom. Typically the junction box is connected to the sensors of two or more nozzle assemblies. The junction box preferably provides an interface such as one or more electrical connectors to connect to a controller (e.g. a cascade controller configured to control the actuators). The interface is configured to transmit the sensor signals to said controller.

[0036] Good results can be achieved, when the processing unit is arranged in a housing attached to the manifold or incorporated into the junction box, in particular formed as a connector box.

[0037] The connector box according to the disclosure may comprise an input interface for connecting at least one sensor. An input interface may be understood as a hardware arrangement configured to receive signals from sensors, typically two or more sensors, and to provide these signals for further processing. One advantage of this arrangement is that multiple sensor inputs can be accommodated within a single connector box, thereby simplifying the wiring and reducing the complexity of the installation.

[0038] An output interface is typically arranged in the connector box for providing output signals to an external controller or output control signals to actuators for adjusting and / or setting the position of the valve needle. An output interface may be understood as a hardware arrangement configured to transmit processed signals to external devices, such as controllers or actuators, to initiate or control their operation.

[0039] It may be provided that the output and / or input interface is arranged on an input-output board, typically a PCB (Printed Circuit Board). An input-output board maybe understood as a printed circuit board designed to accommodate electronic components and circuits necessary for signal input and output functionalities.

[0040] Good results can be achieved when the number of input channels of the input interface is equal to the number of output channels of the output interface. An input channel may be understood as a dedicated pathway or circuit for receiving a sensor signal, and an output channel may be understood as a dedicated pathway or circuit for transmitting control signals to external devices.

[0041] Depending on the design, a logic board is connected to the input-output board for processing sensor signals and generating output signals based thereon. A logic is usually implemented as a printed circuit board comprising electronic components and circuits configured to perform signal processing and logic operations on received sensorsignals. This allows the separation of signal processing functions from input-output functions, allowing specialized optimization of each board for its respective purpose.

[0042] Good results can be achieved when the logic board accommodates an FPGA for processing of the sensor signals. An FPGA (Field-Programmable Gate Array) may be understood as an integrated circuit designed to be configured by the user after manufacturing. This allows flexibility and adaptability' regarding processing of sensor signals

[0043] If appropriate, MOSFETs (metal-oxide-semiconductor field-effect transistors) are arranged on the input-output board for switching of control signals. A MOSFET may be understood as a transistor device characterized by low power consumption and high switching speed.

[0044] For good modularity7, two bus interfaces (in and out) are arranged, typically on the logic board, for daisy-chaining two or more junction boxes. A bus interface may be understood as a standardized communication interface enabling data exchange between multiple electronic devices or modules. In particular real time exchange of data can be provided, which is essential in some applications. Daisy-chaining may be understood as a method of connecting multiple devices sequentially, allowing signals to pass through each device in the chain. One advantage of this arrangement is the enhanced modularity and scalability of the connector box system, facilitating straightforward expansion and integration of additional junction boxes.

[0045] The number of boxes in such a daisy chain typically depends on the number of sensors and / or the type of sensors of the injection mold. In some cases, when temperature and force sensors are present, a first connector box is arranged for processing the signals of the temperature sensors and a second connector box is arranged for processing the signals of the force sensors. The first and the second connector box being daisy chained via their bus interfaces to exchange data. This allows for example to have a single master connector box guiding the injection molding process and one or more slave connector boxes for processing the signals of the sensors connected thereto and providing the (pre-)processed signals to the master connector box via the bus interfaces.

[0046] Depending on the type of sensors, additional hardware may be arranged in the connector box(es) such as signal amplifiers and / or signal converters.

[0047] Typical applications of the hot runner assembly of the disclosure can be injection molds with more than on gate per part; cavities filled in a sequential mode; opening the gates on melt front detection and / or with a specified delay.

[0048] In the following, preferred embodiments of the at least one nozzle assembly of the hot runner assembly are described.

[0049] In a preferred variation the nozzle assembly comprises a nozzle housing comprising a melt channel arranged therein having a valve opening. Depending on the design, the valve opening is formed as a valve gate at a downstream end of the nozzle housing. However, the valve opening can also be arranged upstream of the downstream end of the nozzle housing (i.e. within the melt channel at an intermediate position). A valve needle is arranged in the melt channel displaceable in an axial direction relative to the nozzle housing between a closed position in which the valve needle closes the valve opening and thereby blocks the passage of molten plastic material from the melt channel through the valve opening and an open position in which the valve needle allows passage of molten plastic material from the melt channel through the valve opening. If appropriate, the needle can be brought to intermediate positions between the fully open and the fully closed position to regulate the flow of the material. An actuator comprising an actuator housing is arranged interconnected to the nozzle housing. A drive shaft of the actuator is interconnected to the valve needle to displace the valve needle between the closed position and the open position.

[0050] Preferably a first force sensor is interconnecting the actuator housing and the nozzle housing to determine during operation the forces acting on the valve needle via the actuator housing. In some variations the first force sensor is interconnected to the processing unit for providing a signal related to the molten plastic material injected into the cavity. In this case the first force sensor acts as the at least one sensor of the injection mold as described herein.

[0051] In an assembled state and / or during operation, the first force sensor mechanically interconnects the actuator housing and the nozzle housing. In other words, the first force sensor forms part of the load path of the needle when the actuator displaces the valve needle during operation relative to the nozzle housing between the closed and the open position.

[0052] If appropriate, the signal of the first force sensor is indicative of the forces acting on the valve needle in axial direction during operation. In particular the signal of the first force sensor is indicative for a pressure (or a change thereof) on the valve needle (i.e. a front face of the valve needle).

[0053] Forces acting upon the valve needle can be distinguished as follows: The force, which acts upon the front face of the valve needle, when during operation the injection mold and the valve needle are in a closed position, after the melt has been injected into the cavity, in particular in the holding pressure phase. Forces from shear stress resulting from melt flowing along the valve needle in the melt channel. Dynamic forces resulting from mass inertia during opening and closing of the valve opening by the valve needle driven by the actuator.

[0054] The nozzle assembly according to the disclosure provides a solution for plug and play nozzle assemblies, which can e.g. be used in pre-installed hot runner assemblies. The nozzle assemblies according to the disclosure eliminate the need to place sensors adjacent to or within the cavity of the injection mold. This reduces manufacturing costs and minimizes the risk of damage to (cavity) sensors. In addition, this allows to retrofit nozzle assemblies according to the disclosure in existing injection molds previously not having any sensors, without the need to retrofit any sensors into the existing cavity (cavities respectively).

[0055] Depending on the field of application, the actuator housing is arranged in a floating manner linearly displaceable in the axial direction with respect to the nozzle housing by a linear bearing. The actuator can be a hydraulic actuator or a pneumatic actuator or an electric actuator, depending on the requirements of the application. In case of a hydraulic or pneumatic actuator, the drive shaft is mechanically coupled to a pistonof the actuator. Preferably the drive shaft is integrally formed w ith the piston. A rotation stop can be arranged between the drive shaft and the actuator housing to prevent rotation of the drive shaft with respect to the actuator housing. In particular, when aposition sensor configured to detect the axial position of the piston is attached to the actuator housing.

[0056] In case of an electric actuator, the drive shaft can be of a multi-part design, allowing an electric motor of the electric actuator to be arranged offset from a central axis of the needle.

[0057] In some variations, the linear bearing comprises at least one pillar against which the actuator housing is arranged displaceable. For a stable linear bearing typically more than two, preferably four pillars are foreseen. This arrangement enhances the overall stability’ of the linear bearing.

[0058] Preferably the actuator housing comprises a recess in which the at least one pillar extends. Typically, the actuator housing comprises an individual recess for each pillar respectively. The recess can be formed as a through-bore, wherein in an assembled state the pillar extends through the through-bore such that the linear bearing is provided between the recess and the pillar being arranged displaceable relative to each other.

[0059] In some variations the actuator housing is interconnected to an adjustment arrangement for adjusting the actuator housing with respect to the nozzle housing in axial direction to adjust axial position of the valve needle.

[0060] If appropriate the at least one pillar is fixedly attached to the adjustment arrangement. When four pillars are foreseen, these may form in combination with the adjustment arrangement a mounting cage for the actuator housing. The actuator housing being in the assembled state arranged in a mounting cage in a floating manner. The adjustment arrangement supporting the actuator housing in the axial direction and being configured to adjust the position of the actuator housing in axial direction relative to the mounting cage.

[0061] Good results can be achieved when the first force sensor is arranged between the actuator housing and adjustment arrangement. In particular the first force sensor can be arranged between the actuator housing and the mounting cage.

[0062] Depending on the design, the adjustment arrangement comprises a set screw for adjusting the axial position of the actuator housing with respect to the nozzle housing. The adjustment arrangement may comprise a plate with an opening having an inner thread to receive in an assembled state the set screw. Said plate may act as a top plate of the mounting cage. Preferably the pillars are attached to said top plate.

[0063] The mounting cage may comprise a mounting plate arranged in the assembled state in axial direction opposite to the top plate, wherein the pillars connect the top plate and the mounting plate. The actuator housing being arranged between the top plate and the mounting plate linearly guided by the pillars extending through respective recesses of the actuator housing.

[0064] In a preferred variation, the first force sensor is arranged concentric around a fixing screw fixedly connecting the actuator housing to the adjustment arrangement. If appropriate, the fixing screw- connects the set screws and the actuator housing.

[0065] Alternatively, or in addition, the first force sensor may be arranged concentric around a fixing protrusion of the actuator housing, which fixedly connects the actuator housing to the adjustment arrangement. Said fixing protrusion may comprise an inner and / or outer thread to connect to the adjustment arrangement. The actuator housing can be integrally formed with the fixing protrusion.

[0066] Said fixing screws or fixing protrusion may form a single-point suspension for the actuator housing. Accordingly, forces acting on the actuator housing in axial direction e.g. induced by forces acting on a front face of the valve needle are transmitted to the adjustment arrangement via said single-point suspension. For good results, the mounting cage is during operation arranged fixed in position relative to the nozzle housing.

[0067] Preferably the first force sensor is arranged coaxially with the valve needle. However, an off-axis positioning is thinkable as well, wherein typically two or more first force sensors are arranged symmetrically with respect to a center axis of the needle and / or the drive shaft respectively.

[0068] Alternatively, or in addition, to the first force sensor, a second force sensor can be arranged between the drive shaft of the actuator and a rear end of the valve needle to determine the forces acting on the valve needle, in particular in axial direction. Alternatively, or in addition, the second force sensor can be integrated into the drive shaft of the actuator. In some variations the second force sensor is interconnected to the processing unit for providing a signal related to the molten plastic material injected into the cavity. In this case the second force sensor may act as the at least one sensor of the injection mold as described herein.

[0069] Good results can be accomplished when first force sensor is a piezoelectric sensor. Preferably the first force sensor being preloaded by the fixing screw in an assembled state. This allows to measure both, tension and compression forces in an axial direction of the valve needle. Alternatively, or in addition, the first force sensor may comprise a strain gauge. The same is applicable for the second force sensor, if present.

[0070] Depending on field of application the first force sensor is implemented as a load cell comprising a strain gauge. In some variations the set screw of the adjustment arrangement may act as a load cell.

[0071] In another aspect of the disclosure the valve needle comprises a front face at which a first temperature sensor is arranged. In combination with the first and / or second force sensor great technical advantages can be achieved by determining both, the temperature of the melted plastic material injected into the cavity, as well as the pressure hereof on the front face of the needle. However, a first temperature sensor being arranged at a front face of the valve needle is in principle independent of the disclosure relating to the first (and / or second) force sensor. This aspect therefore forms an independent inventive concept.

[0072] In some variations the first temperature sensor is interconnected to the processing unit for providing a signal related to the molten plastic material injected into the cavity. In this case the first temperature sensor may act as the at least one sensor of the injection mold as described herein.

[0073] Forces determined by the first and / or the second force sensor can be dynamic and / or static loads during operation, such as forces resulting from mass of inertia during displacement of the valve needle in axial direction by the actuator and / or forces resulting from pressure inside the cavity and / or inside the melt channel acting onto the valve needle, in particular a front face of the valve needle arranged e g. adjacent to a cavity wall of a mold cavity in an injection mold.

[0074] Good results are possible, when the first temperature sensor element being arranged for direct thermal contact with the melted plastic material inj ected into the cavity during operation.

[0075] Preferably the first temperature sensor is crimped from the front and welded to the front face of the valve needle. Depending on the desired application, the front end of the valve needle is then manufactured (ground) to match the final geometry of the valve needle.

[0076] The first temperature sensor is preferably a type N thermocouple. The positive leg of the first temperature sensor can be made from NiCroSil and another nickel alloy, NiSil, can be used for the negative leg. The legs of the first temperature sensor may extend through a sleeve partially encapsulating the first temperature sensor. Said sleeve preferably forms part of the front face of the valve needle, allowing direct contact of the first temperature sensor with the melted plastic material injected into the cavity’ during operation.

[0077] For connecting the first temperature sensor, the valve needle comprises a bore extending in longitudinal direction and in which a cable is arranged interconnected to the first temperature sensor arranged at the front face of the valve needle. The bore is preferably a through-bore in axial direction having the first temperature sensor inset intoa front-end of the through-bore. The cable exits the valve needle at a rear end arranged opposite to the front-end of the valve needle.

[0078] The drive shaft preferably comprises a recess extending in axial direction for partially accommodating the cable of the first temperature sensor allowing the cable to not bend beyond its minimal bending radius when being routed laterally away from the drive shaft.

[0079] To support the cable of the first temperature sensor, in particular when the drive shaft displaces the thereto connected valve needle during operation between the closed and the open position, a cable support element is arranged at the drive shaft for guiding the cable in a lateral direction away from the drive shaft. The support element preferably comprises a guide surface having a curvature equal or greater to a minimal bending radius of the cable. This prevents damage to the cable, as bending the cable beyond its minimal bending radius is prevented.

[0080] For easy installation the drive shaft is interconnected to a rear end of the valve needle by a quick release coupling.

[0081] Alternatively, or in addition, to the first temperature sensor, a second temperature sensor is arranged at a front end of the nozzle housing. Preferably the nozzle housing comprises a front face at which the second temperature sensor is arranged. In some variations the second temperature sensor is interconnected to the processing unit for providing a signal related to the molten plastic material injected into the cavity. In this case the second temperature sensor may act as the at least one sensor of the injection mold as described herein.

[0082] For connecting the second temperature sensor, the nozzle housing comprises a channel extending at least partially along the outer surface of the nozzle housing in which a cable interconnected to the second temperature sensor is arranged.

[0083] Depending on the design, the nozzle housing is of a multi-part design comprising an essentially tubular body and a tip bushing. The tip bushing may be attached to the body by a threaded connection. The second temperature sensor element can bearranged in the tip bushing. Preferably a front face of the tip bushing is configured to be embedded into a cavity of an injection mold. Good results are possible, when the second temperature sensor is inset into the front face of the tip bushing to directly determine the temperature of melted plastic material injected into the cavity.

[0084] The valve needle can be essentially tubular. The front end of the valve needle can, depending on the application, have different geometries, such as cylindrical or conical.

[0085] In some variations centering means are arranged in the nozzle housing for centering the valve needle in a radial direction during operation when moved between the open and the closed position. The needle centering means preferably comprise at least one fin extending in radial direction which has on the inside a guiding surface during operation centering the needle in radial direction.

[0086] 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.BRIEF DESCRIPTION OF THE DRAWINGS

[0087] 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:

[0088] Fig. 1 a schematic illustration of an injection mold according to the disclosure;

[0089] Fig. 2 two block diagrams each illustrating a variation (2a and 2b) of an injection mold according to the disclosure in an injection molding machine;

[0090] Fig. 3 a perspective view of a first variation of an injection mold according to the disclosure;

[0091] Fig. 4 another perspective view of the hot runner assembly of the first variation of Fig. 3;

[0092] Fig. 5 a perspective view of a partially sectioned hot runner assembly comprising a first variation of a nozzle assembly according to the disclosure;

[0093] Fig. 6 an exploded view of the first variation of Fig. 1;

[0094] Fig. 7 a perspective view of a partially sectioned hot runner assembly comprising a second variation of a nozzle assembly according to the disclosure;

[0095] Fig. 8 a perspective view of a partially sectioned hot runner assembly comprising a third variation of a nozzle assembly according to the disclosure:

[0096] Fig. 9 a perspective view of a partially sectioned drive shaft of a nozzle assembly according to the disclosure;

[0097] Fig. 10 the drive shaft of Fig 9 in another perspective and sectioned view;

[0098] Fig. I l a perspective view of a front end of a first variation of a valve needle according to the disclosure, as well as a section view indicated by section line BB;

[0099] Fig. 12 a perspective view of a front end of a second variation of a valve needle according to the disclosure, as well as a section view indicated by section line CC; and

[0100] Fig. 13 a perspective view of a connector box according to the disclosure.DESCRIPTION OF THE EMBODIMENTS

[0101] 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 featuresare 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.

[0102] Figure 1 shows a schematic illustration of an injection mold 1 according to the disclosure. In Figure 2 two block diagrams illustrate two variations (Figure 2a and Figure 2b) of an injection mold 1 according to the disclosure. Figures 3 shows perspective view of a first variation of an injection mold 1 with a first mold half 2 and a hot runner assembly 6 according to the disclosure and Figure 4 shows a perspective view of the hot runner assembly 6 of Figure 3.

[0103] The injection mold 1 schematically shown in Figure 1 comprises a first mold half 2 and a second mold half 3 separable at a separation plane 4. Usually the mold halves 2, 3 are arranged displaceable with respect to each other relative to the separation plane 4. Typically, the first mold half 2 housing the hot runner assembly 6 is stationary during operation, while the second mold half 3 is displaced relative thereto between a closed configuration in which cavities 5 are formed between the mold halves 2, 3 and an open configuration in which plastic parts formed in the cavities 5 are demolded.

[0104] The shown hot runner assembly 6 comprises four nozzle assemblies 101 attached to a common manifold 127. The upper two nozzle assemblies 101 are fluidly connected to a common cavity 5, whereas the lower two nozzle assemblies 101 are fluidly connected to individual cavities 5. Each nozzle assembly 101 comprise at least one sensor, in this case at least one first force sensor 109 arranged mechanically connected to a valve needle 104 of the respective nozzle assembly 101 and a first temperature sensor 119 arranged at a tip of the valve needle 104.

[0105] The sensors 109, 119 of the hot runner assembly 6, in particular the shown sensors at the nozzle assemblies 101, are interconnected to a processing unit 8. These connections a indicated by dotted lines. The processing unit 8 is arranged in a housing 11 attached to a mold frame 12 of the first mold half 2. The processing unit 8 comprises atleast one processor 9 configured to process signals of the sensors 109, 119 and to control actuators 106 of the nozzle assemblies 101 based at least partially on the received signals to actuate the valve needles 104. The processor 8 can be implemented as a micro controller or a CPU or the like.

[0106] In the shown variation, the actuators 106 are hydraulically operated. The actuators 106 are fluidically interconnected to valves 13, in particular solenoid valves, indicated by dashed lines. The valves 13 are interconnected to the processing unit 8 to receive signals therefrom in order to open / close the valves 13. This way the processing unit 8 controls the actuators 106.

[0107] In the shown variation, the processing unit 8 as well as the valves 13 are connected to a common power supply 10, in particular an AC power supply providing preferably mains power (110 VAC or 230V AC). The processing unit 8 is configured to receive AC as an input current, however the processing unit 8 may be configured to internally work with a current / voltage different to the input current / voltage. Therefore, the processing unit 8 may comprise a power supply unit for converting the input current / voltage.

[0108] As best visible in Figures 2a and 2b, the power supply 10 can be implemented as or provided by a temperature controller 19, wherein an output channel of the temperature controller 19 is used to supply power - instead to a heating element - to the processing unit 8 and / or to the valves 13.

[0109] Depending on the filed of application, the temperature controller 19 can be integrated into the processing unit 8, as shown in Figure 2b.

[0110] In the variations of Figures 2a and 2b, the processing unit 8 comprises several interfaces to connect to the external devices. These interfaces include an IMM interface 14 to connect to the injection molding machine 18. Further an HMI interface 15 can be foreseen to connect to an HMI (such as a display) for exchanging information with a user. The HMI can form part of the injection molding machine 18 or of a separate temperature controller 19. Typically, a power supply interface 20 is arranged to connect to a power supply 10.

[0111] Depending on the design, the processing unit 8 may comprise a sensor interface 16 typically implemented as one or more connectors. This allows detaching the processing unit 8 e.g. for maintenance or replacement of the processing unit. However, the sensors 109, 119 can also be hard-wired with the processing unit 8, in particular when the processing unit 8 is attached to a nozzle assembly 101.

[0112] In case hydraulic actuators 106 are used in the nozzle assembly 101 to actuate the valve needle, valves 13 are controlled by the processing unit 8, which in turn feed (pressurized) fluid into chambers of the actuator housing to move a piston to which the respective valve needle is attached. The valves 13 typically comprise a hydraulic interface 21 for interconnection to a hydraulic source. The hydraulic source can be provided by the injection molding machine or separately.

[0113] In Figure 3 an exemplary injection mold 1 according to the disclosure is shown comprising a first mold half 2 and a second mold half (not shown) forming in a closed configuration a cavity 5 at a separation plane 4. The shown injection mold 1 comprises three nozzle assemblies 101 attached to a common manifold 127. The manifold 127 receives during operation melted plastic material (melt) from the injection molding machine and distributes the melt in melt channels to each of the nozzle assemblies 101. Each nozzle assembly 101 comprises a nozzle housing 102 and a valve opening 103, through which the melt is during operation injected into the cavity 5. This is preferably done by opening the valve openings 103 in a sequential manner (not simultaneously). A high part quality is possible, when the processing unit 8 arranged in the housing 11 controls the opening of the valve openings 103 based on the position of a melt front moving through the cavity 5 once a first valve oping 103 is opened. In particular, the processing unit 8 sends a signal to the respective valve to actuate the actuator 106 to open the valve opening 103 of the nozzle assembly 101 where a signal of a temperature sensor 119 at the valve opening 103 (e.g. arranged in a tip of the valve needle) is indicative of the melt front to have reached said nozzle assembly 101. Delays between the detection of the melt front and transmission of the “open” signal to the valve can be set via the HMI interface and / or determined by the processing unit 8.

[0114] As visible in Figures 3 and 4, is the housing 11 of the processing unit 8 incorporated into one or more connector boxes 17. This allows to arrange the IMM interface 14, the HMI interface 15, the power supply interface 20 in a traditional manner e.g. incorporated into one or more “Harting” connectors, however other connectors are possible as well.

[0115] Figure 4 shows the hot runner assembly 6 of the injection mold 1 of Figure 3, wherein also the valves 13 for the three nozzle assemblies 101 are shown, including the hydraulic interface 21 for connecting the valves 13 to a hydraulic source. In addition to the indicated first force sensor 106 and the first temperature sensor 119, a position sensor can be arranged at the housing 107 of an actuator 106, for detecting the position of the valve needle 104 with respect to nozzle housing 102 and in particular with respect to the valve opening.

[0116] Figure 5 shows a hot runner assembly 126 comprising a first variation of a nozzle assembly 101 according to the disclosure. Figure 6 shows the first variation of the nozzle assembly 101 of Figure 7 in an exploded view.

[0117] The nozzle assembly 101 comprises a nozzle housing 102 attached to a manifold 127. In the shown variation, the nozzle housing 102 is attached to the manifold 127 by a threaded connection in a sealing manner. The nozzle housing 102 comprises a melt channel 105 receiving during operation melted plastic material from the manifold 127. A valve needle 104 is arranged in the melt channel 105 displaceable between a closed position and an open position. In the closed position the valve needle closes a valve opening 103, such that no melted plastic material can flow through. In the open position the valve needle 104 allows melted plastic material to flowthrough. In the first variation, the valve opening 103 is arranged at a front end 123 of the nozzle housing 102.

[0118] Opposite of the nozzle housing 102 relative to the manifold 127 an actuator 106 is arranged. The actuator 106 comprises an actuator housing 107 and a drive shaft 108. Said drive shaft 108 is in an assembled state detachably connected to a rear end 117 of the valve needle 104, to displace the valve needle 104 during operation between the open and the closed position. The shown actuator 106 is e.g. a pneumatic or ahydraulic actuator comprising a piston 137 displaceable in the actuator housing 107 in the axial direction z. A rotation stop 131 is arranged between the piston 137 and the actuator housing 107 to prevent rotation of the drive shaft 108 with respect to the actuator housing 107.

[0119] A first force sensor 109 is arranged on an upper side of the actuator housing 107. Said first force sensor 109 arranged in a load path from the valve needle 104 via the drive shaft 108, the piston 137 and the actuator housing 107 to the nozzle housing 102 to determine the forces acting on the valve needle 104.

[0120] In the shown variations the actuator housing 107 is arranged in a mounting cage comprising a top plate 128. a mounting plate 129 and four pillars 111 extending in axial direction z between the top plate 128 and the mounting plate 128. The actuator housing 107 comprises four recesses for respectively receiving each a pillar to form a linear bearing 109 of the actuator housing 107 in the mounting cage in axial direction z. The actuator housing 107 is attached to the top plate 128 of the mounting cage. The mounting plate 129 of the mounting cage is attached to the manifold 127 and therefore fixed in position relative to the nozzle housing 102 completing the load path.

[0121] The first force sensor 109 is in the first variation arranged in axial direction z between the upper side of the actuator housing 107 and the top plate 128 of the mounting cage. This first variation comprises an adjustment arrangement 113 arranged at the top plate 128. The adjustment arrangement 113 comprises a set screw 114 and a fixing screw 115. The set screw 114 comprises an outer thread and is arranged in an opening of the top plate 128 having an inner thread to engage with the set screw 114, such that the axial position of the set screw 114 is adjustable by turning said set screw 114. The fixing screw 115 fixedly connects the set screw' 114 and the actuator housing 107. As can be seen in Figure 6, the first force sensor 109 is essentially ring shaped and arranged concentric around the fixing screw' 115. In this arrangement, the first force sensor 109 is also coaxial with the valve needle 104.

[0122] In the first variation, as shown in Figure 5, the first force sensor 109 is a piezoelectric force sensor, w herein the fixing screw 115 clamps the first force sensor 109 between the actuator housing 107 and the set screw 114 thereby pre-loading the sensor.

[0123] In addition to the first force sensor 109 a first temperature sensor 119 is foreseen. The valve needle 104 comprises a front face 119 at which the first temperature sensor 119 is arranged. As best visible in Figures 11 and 12, the first temperature sensor 119 is arranged in a bore 120 (through-bore) extending in axial direction z. The first temperature sensor 119 comprises two legs 135 (a positive and a negative) which extend in axial direction z to the front face 118 of the valve needle 104. The front face 118 of the valve needle 104 is partially formed by a sleeve 136 of the first temperature sensor 119, being inset into the bore 120. A cable 121 of the first temperature sensor 119 extends along the bore 120 and exits the bore 120 at a rear end 117 of the valve needle 104. The first variation of the valve needle 104, as shown in Figure 11 has a conical front section. In difference thereto the second variation of the valve needle 104 has, as shown in Figure 12, a cylindrical front section.

[0124] The rear end 117 of the needle is attached to the drive shaft 108 of the actuator 106. This is shown in Figures 9 and 10. The drive shaft comprises a quick release coupling 125 for detachably connecting to the read end 117 of the valve needle 104. The insertion of the rear end 117 into the quick release coupling 125 is indicated in Figure 10 with dashed lines. The drive shaft 108 comprises a recess 130 extending in axial direction z for partially accommodating the cable 121. In addition, a cable support element 132 is arranged at the drive shaft 108 to guide the cable 121 from the recess 130 laterally aw ay from the drive shaft 108. The cable 121 is guided by a guide surface 138 of the cable support element 132 having a curvature greater or equal to a minimal bending radius of the cable 121.

[0125] In Figure 7 a second variation of a nozzle assembly 101 according to the disclosure is shown. The second variation differs from the first variation, in that a second temperature sensor 122 is arranged at a front end 123 of the nozzle housing 102 and a second force sensor 116 is arranged at the drive shaft 108. The second temperature sensor122 is inset into a front face of a tip bushing 39 of the nozzle housing 102. The second force sensor 116 is resting against the rear end 117 of the valve needle.

[0126] In Figure 8 a third variation of a nozzle assembly 101 according to the disclosure is shown. The third variation differs from the first and the second variation, in that the first force sensor 109 is formed as a load cell 133 comprising a strain gauge 134. In the shown variation, the load cell 133 acts as the set screw 114 of the first and the second variation by which the axial position of the actuator housing 107 relative to the manifold 127 and consequently to the nozzle housing 102 can be adjusted.

[0127] In Figure 13 a perspective exploded view7of a connector box 17 according to the disclosure is shown. The connector box 17 comprises a housing 11 formed by an upper and a lower part, configured to receive and protect the internal electronic components. The lower part of the housing 11 is usually attached to the injection mold 1 or to the hot runner assembly 6 and comprises an opening for routing cables from the sensors into the housing 11 and to the sensor interface 16.

[0128] Arranged within the housing 11 is an input-output board 23 on which the (input) sensor interface 16 and an output interface 22 is mounted. The input-output board 23 is configured to receive signals from multiple sensors and route them for further processing. Mounted directly beneath the input-output board 23 a logic board 24 is arranged connector to the input-output board 23. The logic board 24 being designed for processing the incoming sensor signals and generating corresponding output signals. The logic board 24 accommodates a bus interface 25 for incoming data and a bus interface 26 for outgoing data, enabling daisy -chaining of multiple connector boxes and facilitating modular integration. A power supply interface 21 and an IMM interface 14 are arranged at the upper part of the connector box 17 for integration with the injection molding system. In addition, the output interface 22 can be connected to the connector arranged at the upper part of the housing 11. Furthermore, aHMI interface can be provided.

[0129] Depending on the design, the processing unit 9 can be arranged on the logic board 24 or a separate board (not shown) in the connector box 17. In this case theoutput interface 22 is interconnected to the valves 13 for sending control signals to the same.

[0130] Alternatively, the processing unit 9 can be arranged in a separate connector box 17. typically acting as the master connector box, when two or more connector boxes 17 are daisy chained together.

[0131] 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 DESIGNATIONS1 Injection mold 26 Bus interface (out)2 First mold half3 Second mold half 101 Nozzle assembly4 Separation plane 102 Nozzle housing5 Cavity- 103 Valve opening6 Hot runner assembly 104 Valve needle8 Processing unit 105 Melt channel9 Processor 106 Actuator10 Power supply- 107 Actuator housing11 Housing (processing unit) 108 Drive shaft (actuator)12 Mold frame (first mold half) 109 First force sensor13 Electric Valve 110 Linear bearing14 IMM interface 111 Pillar (linear bearing)15 HMI interface 112 Recess (actuator housing)16 Sensor interface (input) 113 Adjustment arrangement17 Connector box 114 Set screw (adjustment18 Injection molding machine arrangement)(IMM) 115 Fixing screw (adjustment19 Temperature controller arrangement)20 Power supply interface 116 Second force sensor21 Hydraulic interface 117 Rear end (valve needle)22 Output interface 118 Front face (valve needle)23 Input-output board 119 First temperature sensor24 Logic board 120 Bore (valve needle)25 Bus interface (in) 121 Cable (first temperature sensor)Second temperature sensorFront end (nozzle housing)Front face (nozzle housing)Quick release couplingHot runner assemblyManifoldTop plateMounting plateRecess (drive shaft)Rotation stopCable support elementLoad cellStrain gaugeLeg (temperature sensor)Sleeve (temperature sensor)Piston (actuator)Guide surface (cable support element)Tip bushing (nozzle housing

Claims

PATENT CLAIMS1. Injection mold (1) comprising a first mold half (2) and a second mold half (3) interacting with each other during operation along a separation plane (4) between an open and a closed position, forming in the closed position at least one cavity' (5) there between and a hot runner assembly (6) arranged at the first mold half (2), wherein a. the hot runner assembly (6) comprising a manifold (127) and at least one thereto interconnected nozzle assembly (101) to inject during operation molten plastic material from a melt channel (105) into at least one thereto interconnected cavity (5) of the injection mold (1); b. the at least one nozzle assembly (101) comprising a valve opening (103) and a valve needle (104) arranged displaceable by an actuator (106) between i. a closed position in which the valve needle (104) closes the valve opening (103) and thereby blocks the passage of molten plastic material from the melt channel (105) through the valve opening (103) and ii. an open position in which the valve needle (104) allows passage of molten plastic material from the melt channel ( 105) through the valve opening (103); c. at least one sensor (109, 116, 119, 122) interconnected to the cavity (5) for providing a signal related to the molten plastic material injected into the cavity (5); and d. a processing unit (8) being interconnected to the at least one sensor (109, 116, 119, 122) and to an actuator (106) of at least one nozzle assembly (101) andbeing configured for adjusting and / or setting the position of the valve needle (104) by the actuator (106) based on a signal received from the sensor (109, 1 16, 119. 122).

2. Injection mold (1) according to claim 1, wherein the processing unit (8) is arranged in a housing (11) attached to or incorporated in the first mold half (2).

3. Injection mold (1) according to claim 2, wherein the housing (1 1) of the processing unit (8) attached to a mold frame (12) of the first mold half (2) and / or the manifold (127) and / or the nozzle assembly (101) and / or the actuator (106).

4. Injection mold (1) according to claim 2 or 3, wherein the housing (11) of the processing unit (8) is a connector box (17) by which the processing unit (8) is interconnected to an injection molding machine (18) in which the injection mold (1) is arranged during operation.

5. Injection mold (1) according to any of the preceding claims, wherein the actuator (106) is a pneumatic or hydraulic actuator driven by an electric valve (13) interconnected to processing unit (8), wherein a. the electric valve is operatable with a similar voltage as the processing unit (8); and / or b. the electric valve (13) and the processing unit (8) are AC-drivable.

6. Injection mold (1) according to claim 5, wherein the electric valve (13) and the processing unit (8) are operatable by a common power supply (10), in particular by an external temperature controller (19).

7. Injection mold (1) according to any of the preceding claims, wherein alternatively, or in addition, to the at least one sensor (109, 1 16, 1 19, 122) the processing unit (8) is interconnectable to the injection molding machine (18) interconnected during operation to the cavity7(5) for supplying the molten plastic material injected into the cavity (5), wherein the processing unit (8) is configured to receive a signal related to the molten plastic material injected into the cavity (5) from the injection molding machine (18).

8. Injection mold (1) according to any of the preceding claims, wherein the nozzle assembly (101) comprising: a. a nozzle housing (102) comprising a melt channel (105) arranged therein merging into the valve opening (103); b. the valve needle (104) being arranged in the melt channel (105) displaceable in an axial direction (z) relative to the nozzle housing (102) between i. the closed position in which the valve needle (104) closes the valve opening (103) and thereby blocks the passage of molten plastic material from the melt channel (105) through the valve opening (103) and ii. the open position in which the valve needle (104) allows passage of molten plastic material from the melt channel (105) through the valve opening (103); c. an actuator (106) comprising i. an actuator housing (107) interconnected to the nozzle housing (102) and ii. a drive shaft (108) interconnected to the valve needle (104) to displace the valve needle (104) between the closed position and the open position;d. wherein the at least one sensor (109, 116, 119, 122) is a first force sensor (109) interconnected to the processing unit (8), said a first force sensor (109) interconnecting the actuator housing (107) and the nozzle housing (102) to determine during operation the force acting on the valve needle (104) via the actuator housing (107).

9. The injection mold (1) according to claim 8, wherein the actuator housing (107) is arranged in a floating manner linear displaceable in axial direction (z) with respect to the nozzle housing (102) by a linear bearing (110).

10. The injection mold (1) according to claim 9, wherein the linear bearing (110) comprises at least one pillar (111) against which the actuator housing is arranged displaceable.

11. The injection mold (1) according to claim 10, wherein the actuator housing (107) comprises a recess (112) in which the pillar (111) extends.

12. The injection mold (1) according to any of the claims 9 to 1 1, wherein the actuator housing (107) is interconnected to an adjustment arrangement (113) for adjusting the actuator housing (107) with respect to the nozzle housing (102) in axial direction (z) to adjust axial position of the valve needle (104), in particular by a set screw (114) of the adjustment arrangement (113).

13. The injection mold (1) according to claim 11, wherein the first force sensor (109) is arranged between the actuator housing (107) and adjustment arrangement (113).

14. The injection mold (1) according to claim 12 or 13, wherein the first force sensor (109) is arranged concentric around a fixing screw (115) fixedly connecting the actuator housing (107) to the adjustment arrangement (113).

15. The injection mold (1) according to at least one of the previous claims, wherein the first force sensor (109) is arranged coaxially with the valve needle (104).

16. The injection mold (1) according to any of the preceding claims, wherein the at least one sensor (109. 116, 119. 122) is alternatively or in addition to the first force sensor (109), a second force sensor (116) is arranged between the drive shaft (108) of the actuator (106) and a rear end (117) of the valve needle (14) to determine the forces acting on the valve needle (104) and / or the second force sensor (116) is integrated into the drive shaft (108) of the actuator (106) interconnected to the processing unit (8).

17. The injection mold (1) according to any of the preceding claims, wherein the first force sensor (109) being a piezoelectric sensor, in particular preloaded by the fixing screw (115) in an assembled state.

18. The injection mold (1) according to any of the preceding claims, wherein the valve needle (104) comprises a front face (118) at which a first temperature sensor (119) is arranged interconnected to the processing unit (8).

19. The injection mold (1) according to claim 18, wherein the valve needle (104) comprises a bore (110) extending in longitudinal direction (z) and in which a cable (121) is arranged interconnected to the first temperature sensor (119) arranged at the front face ( 118) of the valve needle (104).

20. The injection mold (1) according to any of the preceding claims, wherein a second temperature sensor (122) is arranged at a front end (123) of the nozzle housing (102).

21. The injection mold (1) according to claim 20, wherein the nozzle housing (102) comprises a front face (124) at which the second temperature sensor (122) is arranged.

22. The injection mold (1) according to claim 20 or 21, wherein the nozzle housing (102) comprises a channel (105) extending at least partially along the outer surface of the nozzle housing (102) in which a cable interconnected to the second temperature sensor (122) is arranged.

23. The injection mold (1) according to any of the preceding claims, wherein the drive shaft (108) is interconnected to a rear end (117) of the valve needle (104) by a quick release coupling (125).

24. Hot runner assembly (6) configured for use in an injection mold (1) according to any of the previous claim 1 to 23, the hot runner assembly comprising a. a manifold (127) and at least one thereto interconnected nozzle assembly (101) to inject during operation molten plastic material from a melt channel (105) into at least one thereto interconnected cavity (5) of the injection mold (1); b. the at least one nozzle assembly (101) comprising a valve opening (103) and a valve needle (104) arranged displaceable by an actuator (106) between i. a closed position in which the valve needle (104) closes the valve opening (103) and thereby blocks the passage of molten plastic material from the melt channel (105) through the valve opening (103) and ii. an open position in which the valve needle (104) allows passage of molten plastic material from the melt channel (105) through the valve opening (103); c. at least one sensor (109.

116. 119, 122) interconnected to the cavity (5) for providing a signal related to the molten plastic material injected into the cavity (5); andd. a processing unit (8) being interconnected to the at least one sensor (109, 116, 1 19, 122) and to an actuator (106) of at least one nozzle assembly (101) and being configured for adjusting and / or setting the position of the valve needle (104) by the actuator (106) based on a signal received from the sensor (109, 116, 1 19, 122).

25. The hot runner assembly (6) according to claim 24, wherein the processing unit (8) is arranged in a housing (11) attached to the manifold (127) or incorporated into a junction box, in particular a connector box (17).

26. Hot runner assembly (6) configured for use in an injection mold (1) according to any of the previous claim 1 to 23, the hot runner assembly comprising a. a manifold (127) and at least one thereto interconnected nozzle assembly (101) to inject during operation molten plastic material from a melt channel (105) into at least one thereto interconnected cavity (5) of the injection mold (1); b. the at least one nozzle assembly (101) comprising a valve opening (103) and a valve needle (104) arranged displaceable by an actuator (106) between i. a closed position in which the valve needle (104) closes the valve opening (103) and thereby blocks the passage of molten plastic material from the melt channel (105) through the valve opening (103) and ii. an open position in which the valve needle (104) allows passage of molten plastic material from the melt channel (105) through the valve opening (103); c. a processing unit (8) being interconnectable toi. at least one sensor (109, 116, 119, 122) interconnected to the cavity (5) for providing a signal related to the molten plastic material injected into the cavity (5); and / or ii. an injection molding machine (18) supplying during operation molten plastic material injected into the cavity (5); d. the processing unit (8) is interconnected to an actuator (106) of at least one nozzle assembly (101) and being configured for adjusting and / or setting the position of the valve needle (104) by the actuator (106) based on a signal received from the sensor (109, 116, 119, 122) and / or based on a signal received from the injection molding machine (18).

27. The hot runner assembly (6) according to claim 26, wherein the processing unit(8) is arranged in a housing (11) attached to the manifold (127) or incorporated into a junction box, in particular a connector box (17).

Images