Sensor component, injection molding machine with sensor component and method for detecting a deposit

Abstract

Sensor component (11) for detecting deposits (20) of injection molding material on an injection molding machine (1), comprising a holder (14) and one or more sensors (15) arranged on or in the holder (14), wherein the holder (14) is designed to be arranged at a defined distance (d) from an outer wall (23) of an injection molding machine (1), comprising one or more spacers (18) for holding the holder (14) at the defined distance (d) from the outer wall (23), wherein the one or more spacers (18) are designed as springs.

Description

[0001] The present invention relates to a sensor component for detecting undesired deposits of injection molding material on an injection molding machine, in particular in plastic injection molding technology.

[0002] During the operation of injection molding machines, unwanted deposits of injection molding material can form, for example, in the area of ​​an injection nozzle or on the outside of an injection molding machine cylinder. Such deposits can occur, in particular, due to leaks at interfaces between various components of the injection molding machine or due to other malfunctions.

[0003] This can lead to damage to parts of the injection molding machine. Heating elements, especially heating sleeves, and / or temperature sensors may be located in the area of ​​the injection nozzle. The heating elements and temperature sensors serve to control or monitor the temperature of the injection nozzle. Overmolding of the injection nozzle and cylinder, which occurs in the event of a fault, can lead to the costly destruction of the heating sleeves and temperature sensors. The system must then be stopped and cooled down to clean the overmolding areas. Both the destruction of the parts and the sometimes lengthy downtimes for cleaning or replacement lead to high costs.

[0004] Unwanted material leakage is currently monitored visually by employees. If overspray from the injection nozzle and / or cylinder is detected, the injection molding machine must be manually stopped to prevent damage. Visual inspection is error-prone, and critical overspray is often not detected in time.

[0005] WO 02 / 045 937 A1 discloses a device that makes it possible to detect the formation of a plastic leak between the nozzle of the cylinder of an injection molding machine and the nozzle receptacle of the mold installed therein. A sensor is arranged at a distance around the injection molding machine, without mechanical contact with the injection press.

[0006] CN 1 08 381 887 A describes a sensor for an injection moulding machine which is clamped onto the injection moulding machine.

[0007] JP S63- 82 520 U, JP H03- 116 911 U, DE 297 13 366 U1, DE 20 2019 101 757 U1 and JP S60- 142 914 U describe further sensors for detecting deposits on injection molding machines.

[0008] The object of the present invention is to provide an improved injection molding machine and a sensor component.

[0009] According to one embodiment, a sensor component for detecting deposits of injection molding material on an injection molding machine comprises a holder and one or more sensors arranged on or in the holder. The holder is designed to be arranged at a defined distance from an outer wall of the injection molding machine.

[0010] In this way, heat transfer from temperature-controlled areas of the injection molding machine to the mount and thus to the sensors can be reduced, preventing the sensors from being damaged by high temperatures. For this purpose, a clearance can be provided between the mount and the outer wall. The distance between the mount and the outer wall is, for example, at least a quarter of the diameter of the outer wall at the mount's location.

[0011] The holder can be designed to be circumferential. The holder can be designed to be completely or partially circumferential. For example, the holder can be ring-shaped or partially ring-shaped.

[0012] The sensors can, for example, be temperature sensors that detect a temperature change in a monitored area, in particular a temperature increase or decrease due to unwanted deposits of injection molding material. They can also be optical sensors, in particular distance sensors. It is also possible for one or more sensors to be designed as temperature sensors and one or more sensors as optical sensors. One or more sensors can also be designed as a camera, for example, an infrared camera or other image recognition device.

[0013] The sensors can be arranged and aligned such that they can detect deposits in one direction relative to a longitudinal axis. It is also possible for the sensors to be arranged and aligned such that they can detect deposits in multiple areas, particularly in opposite directions relative to a longitudinal axis.

[0014] The sensor component has one or more spacers to maintain the mount at a defined distance from the outer wall. The spacers are designed as springs, for example, as spiral springs. A large number of coils minimizes heat transfer to the mount.

[0015] The sensor component can have a fastening element for attaching the bracket to the outer wall. For example, the fastening element is attached directly to the area of ​​the outer wall surrounded by the bracket. For example, the fastening element can be a clamping ring. Such a fastening element allows for simple and flexible attachment to the outer wall. Injection molding machines can also be easily retrofitted with the sensor component.

[0016] It is also possible for the sensor component not to be designed for attachment to the outer wall. In particular, the sensor component cannot be attached to the injection molding machine in the area around which the holder is guided. For example, the sensor component has a carrier that supports the holder and is arranged separately from the wall. This prevents direct heat transfer from the outer wall, especially high-temperature areas of the outer wall, to the holder.

[0017] The sensor component can include one or more additional electronic components. The electronic components can, for example, be configured as an evaluation and / or alarm unit for forwarding and evaluating the sensor signals and / or for issuing an alarm upon detection of a critical deposit, or can be configured to forward signals to such units. It is also possible for the evaluation and / or alarm unit to be connected to the control system of the injection molding machine and to lead to an automatic stop of the injection molding machine in the event of a fault.

[0018] The sensor component may also include one or more temperature sensors for monitoring the temperature of one or more components of the sensor component, such as the bracket, sensors and / or electronics.

[0019] The sensor component can also include a cooling device for cooling one or more components of the sensor component. For example, the cooling device is controlled by a temperature sensor.

[0020] According to one embodiment, an injection molding machine with a sensor component is provided. The sensor component can have one, several, or all properties of the previously described sensor component.

[0021] The injection molding machine has an outer wall around which the holder is arranged. This can be, for example, a wall of the injection nozzle, a cylinder in which injection molding material is melted and propelled, or a component between the injection nozzle and the cylinder. In particular, this can be a component that is exposed to high temperatures during operation.

[0022] For example, the sensors are designed to monitor an area around the injection nozzle. It is also possible for the sensors to be designed to monitor an area around a junction between different components of the injection molding machine. One or more sensors can also be aligned in one direction relative to the longitudinal axis, and one or more sensors can be aligned in the opposite direction.

[0023] For example, the bracket is positioned near the area to be monitored. The bracket is positioned at a defined distance around the wall so that the sensors and other electronics are not damaged by high temperatures.

[0024] According to a further embodiment, a method for detecting unwanted deposits of injection molding material on an injection molding machine is provided. An injection molding machine with a sensor component is provided. An injection molding machine can also be provided that is retrofitted with the sensor component. The injection molding machine and the sensor component can have one, several, or all of the properties described above.

[0025] The sensors are aligned to monitor one or more areas of the injection molding machine. During operation, the sensors detect deposits of injection molding material on the injection molding machine. An evaluation and / or alarm unit can evaluate the signals and forward them to a user or the injection molding machine's control system. If a critical deposit is detected, an alarm signal can be issued or the injection molding machine can be automatically stopped.

[0026] The present invention encompasses several aspects, in particular devices and methods. The features, properties, and embodiments described for one aspect shall also apply accordingly to the other aspect.

[0027] Furthermore, the description of the objects specified here is not limited to the specific embodiments. Rather, the features of the individual embodiments can be combined with one another – as far as technically feasible.

[0028] In the following, the objects described here are explained in more detail using schematic embodiments.

[0029] They show: Fig. 1 a detail of an injection molding machine in longitudinal section, Fig. 2 an embodiment of an injection molding machine with sensor component according to the invention in a side view with partial sectional view, Fig. 3 an embodiment of a sensor component according to the invention in sectional view, Fig. 4 the inventive embodiment of the sensor component from Fig. 3 in a first operating mode, Fig. 5 the embodiment of the sensor component from Fig. 3 in a second operating mode, Fig. 6 a non-inventive example of an injection molding machine with sensor component in a side view with partial sectional view, Fig. 7 a non-inventive example of a sensor component in sectional view, Fig. 8 shows an embodiment of a sensor component according to the invention in a sectional view, Fig. 9 an embodiment of a sensor component according to the invention in sectional view.

[0030] Preferably, in the following figures, like reference numerals refer to functionally or structurally corresponding parts of the various embodiments.

[0031] Fig. Figure 1 shows a section of an injection molding machine 1, in particular a plastic injection molding machine. The injection molding machine 1 has an injection nozzle 2 through which the molten injection material flows into an injection mold. The injection nozzle 2 is closed and opened by a nozzle closure unit 3.

[0032] The injection molding machine 1 has a cylinder 4 into which the injection molding material, for example in granular form, is fed via a feed system (not shown). The injection molding material is melted in the cylinder 4 and conveyed toward the injection nozzle 2 by a screw 5 or other propulsion mechanism.

[0033] During operation, unwanted leakage of injection molding material may occur, for example, at sealing surfaces between the separation points 6, 8, 10 of various components of the injection molding machine 1. For example, this could be a separation point 6 between the injection nozzle 2 and a nozzle closure housing 7 of the injection molding machine 1, in which the nozzle closure unit 3 is arranged, a separation point 8 between the nozzle closure housing 7 and a head region 9, or a separation point 10 between the head region 9 and the cylinder 4. Depending on the design of the injection molding machine 1, the components and separation points may vary.

[0034] In the event of a malfunction, injection molding material can also leak from the injection nozzle 2 onto the injection molding machine 1 and deposit there. For example, leaks in the nozzle closure unit 3 can lead to unwanted material leakage.

[0035] Such undesirable deposits on the injection molding machine 1 can lead to damage to sensitive areas, such as heating elements and temperature sensors.

[0036] Fig. Figure 2 shows an injection nozzle 2 of an injection molding machine 1, on which a sensor component 11 is arranged to monitor undesired material discharge. This can be the injection nozzle 2 from Fig. 1 or an injection molding machine of a different design.

[0037] For example, heating elements 12 for controlling the temperature of the injection nozzle 2 and a temperature sensor 13 are arranged on the injection nozzle 2. The heating elements 12 are designed as heating sleeves that are arranged around an outer side of the injection nozzle 2. The sensor component 11 is arranged here relative to a longitudinal axis A between the two heating elements 12 and, in particular, is fastened to the injection nozzle 2 between the heating elements 12. The longitudinal axis A corresponds to the injection direction of the material through the injection nozzle 2. In other embodiments, the sensor component 11 can also be arranged at other positions on the injection molding machine 1. It is also possible for an injection nozzle 2 to have no heating elements 12 and then to be heated, for example, by heating elements at a different position on the injection molding machine. In this case, too, the sensor component 11 can be arranged on the injection nozzle 2 or at a different position.

[0038] The sensor component 11 is designed, for example, to detect the accumulation of injection molding material on the heating elements 12 in order to prevent damage to the heating elements 12, to minimize damage, and / or to avoid consequential damage such as fires. The sensor component 11 can also be designed to detect the accumulation of injection molding material at other locations.

[0039] Fig. 3 shows the sensor component 11 in its arrangement on the injection nozzle 2 in a sectional view perpendicular to the longitudinal axis A of the injection nozzle 2.

[0040] The sensor component 11 has a holder 14 designed to accommodate one or more sensors 15. The holder 14 is circumferential, in particular annular. It is also possible for the holder to have a different shape, e.g., be rectangular. Furthermore, the holder 14 can also be only partially circumferential. The holder 14 allows the sensors 15 to be held at a defined distance from an outer side of high-temperature parts of the injection molding machine 1, in particular the injection nozzle 2. For example, four sensors 15 are arranged on or in the holder 14.

[0041] The sensors 15 are arranged, for example, on a front side of the holder 14, with the front side facing in the injection direction. The sensors 15 can also be arranged on a rear side of the holder 14 or, as shown here, can be guided through the holder 14 and configured to detect deposits in different directions. The holder 14 can have recesses or passages for accommodating the sensors 15.

[0042] For example, the sensors 15 can be designed for optical detection of deposits and / or for detection of deposits by temperature measurement, in particular contactless infrared temperature measurement.

[0043] In addition, the sensor component 11 includes electronics 16 for processing and / or forwarding the signals from the sensors 15. The electronics 16 can also be mounted in or on the holder 14.

[0044] The sensor component 11 may also include one or more temperature sensors 28 for monitoring the temperature of the holder 14 or other components of the sensor component 11.

[0045] The sensors 15 are arranged by means of the holder 14 at a defined distance d from the outer wall 23 of the injection molding machine 1. For example, the distance is at least one-quarter of the outer diameter of the outer wall 23. This ensures that the sensors 15 are not damaged by the high temperatures on the outside. In particular, a free space 21 is located at least in some areas between the holder 14 and the outside of the injection molding machine 1.

[0046] The holder 14 is attached to the outside of the injection molding machine 1, in particular to a cylindrical outer wall of the injection nozzle 2, by means of a fastening element 17. The fastening element 17 is, for example, a clamping ring.

[0047] The bracket 14 is attached to the fastening element 17 via spacers 18. The spacers 18 can be springs, in particular coil springs. For example, they are tension springs.

[0048] In this way, the heat transfer from the wall of the injection nozzle 2 to the holder 14 and thus to the sensors 15 can be kept as low as possible. The principle of suspending a "flying ring" in springs reduces heat transfer, since each coil of the springs represents an additional cooling path toward the ring, i.e., the holder 14. Thus, such spacers 18 ensure a "cool suspension" of the holder 14.

[0049] Thus, the holder 14 and thus also the sensors 15 and electronics 16 remain within a temperature range approved for sensitive components. Depending on the application, components of the injection molding machine 1, such as the injection nozzle 2, cylinder 4, nozzle closure housing 7, and head area 9, can be heated to temperatures in the range of 350 °C or higher by means of the heating elements 12.

[0050] Such a mounting is designed to save space and enables simple and quick retrofitting of an injection molding machine 1 with the sensor component 11. By fastening using the fastening element 17 and spacer 18, the sensor component 11 can be easily and flexibly adapted to injection molding machines of different sizes. Minor changes in diameter can be compensated for using a clamping ring and spring suspension. For larger changes in diameter, the size of the holder 14, the fastening element 17, and / or the spacer 18 can be changed. Depending on the size and nature of the area to be monitored, the number and position of sensors 15 and / or electronics 16 can also vary.

[0051] In addition to the use of the sensor component 11 as shown here in the area of ​​the injection nozzle 2, the installation of one or more sensor components 11 further back on the injection molding machine 1, in particular in the area of ​​the cylinder 4, is also conceivable. In particular, one or more sensor components 11 can be positioned in such a way that critical areas, such as the separation points 6, 8, 10 ( Fig. 1). For example, several sensor components 1 can be installed at different locations on an injection molding machine 1.

[0052] Fig. 4 shows the sensor component 11 from Fig. 3 in a training course to detect deposits in the area of ​​the nozzle opening 19.

[0053] The sensors 15 are designed and positioned here to detect deposits 20 of injection molding material in the area of ​​the nozzle opening 19. For example, if, during operation of the injection molding machine 1, molten injection molding material flows from the area of ​​the nozzle opening 19 over the heating element 12 toward the sensor component 11 in the event of a fault, deposits 20 are detected by the sensors 15 and transmitted to the electronics 16.

[0054] The electronics 16 sends a corresponding warning signal to the machine control and / or monitoring device, informing the operator of the critical machine condition. Furthermore, the electronics 16 can also forward data for storage. The electronics 16 can forward this data and warning signal to an on-site facility or, for example, to a cloud service. It is also possible for the operation of the injection molding machine 1 to be automatically interrupted upon detection of the critical machine condition.

[0055] The sensor component 11 can thus prevent or minimize damage caused by leakage of injection molding material by detecting a material leak before sensitive components, such as heating elements 12 and temperature sensors 13, are excessively enveloped by the escaping material.

[0056] Fig. 5 shows the sensor component 11 from Fig. 3 in training to detect deposits in different directions.

[0057] Thus, the sensor component 11 is designed not only to detect deposits 20 in the area of ​​the nozzle opening 19, but also in the opposite direction, for example at the separation point 6 between the injection nozzle 2 and the nozzle closure unit 3.

[0058] For example, one or more of the sensors 15 are configured to detect deposits in one direction, while other sensors 15 are configured to detect deposits in an opposite direction. Depending on the type of sensors 15, it may also be possible for the sensors 15 to simultaneously detect the formation of deposits at multiple locations.

[0059] Both Fig. 4 and Fig. 5 may be different operating modes of the same sensor component 1. It is also possible that the sensors 15 in the Fig. 4 and Fig. 5 are placed and aligned differently.

[0060] Fig. 6 shows a further embodiment of an injection molding machine 1 with sensor component 11. Fig. 7 shows the sensor component 11 in a sectional view.

[0061] In contrast to the sensor component 11 of the Fig. 2 and Fig. 3, the sensor component 11 has a holder 14 that is not attached to an outer wall 23 of the injection molding machine 1, in particular the injection nozzle 2. Instead, the holder 14 is held by a carrier 22, which is, for example, located separately from the injection molding machine 1 or at least located separately from high-temperature components of the injection molding machine 1. Thus, no fastening element 17 is provided here for attaching the holder 14 to the wall 23 of the injection molding machine 1, around which the holder 14 is arranged. In this arrangement, too, a distance d and free space 21 are provided between the wall 23 of the injection molding machine 1 and the holder 14.

[0062] Here, too, no spacers 18 are present. However, it is also possible to provide spacers 18 to ensure the required distance d, but these are not attached to the wall 23.

[0063] Fig. 8 shows a further embodiment of a sensor component 11 in a sectional view.

[0064] The sensor component 11 has a cooling device 24. The cooling device 24 has, for example, one or more cooling channels through which a coolant, such as water, flows. The coolant is supplied through an inlet 25 and discharged through an outlet 26. The cooling device 24 can also be based on cooling by means of other media, such as air.

[0065] The sensor component 11 can otherwise be designed like one of the previously described sensor components with spacers designed as springs, in particular having the sensors 15, electronics 16, and one or more temperature sensors 28. The sensor component 11 can be mounted externally or attached to a wall 23 of the injection molding machine 1.

[0066] For example, the temperature sensor 28 is used to control the cooling device 24.

[0067] Fig. 9 shows a further embodiment of a sensor component 11 in a sectional view.

[0068] The holder 14 is only partially circumferential around the wall 23 and has an interruption 27. For example, the holder 14 is circumferential around at least two-thirds of the wall 23. The interruption 27 can facilitate assembly on the injection molding machine 1. The interruption 27 can also be arranged at positions other than those shown here. For example, the interruption 27 is arranged at the top, bottom, or even to the side. In addition, the interruption 27 can also have advantages for heat transfer. Multiple interruptions 27 can also be provided at different positions.

[0069] The sensor component 11 can otherwise be designed like one of the previously described sensor components. Reference symbol 1 injection molding machine 2 injection nozzles 3 Nozzle closure unit 4 cylinders 5 snail 6 Separation point 7 Nozzle closure housing 8 Separation point 9 Head area 10 Separation point 11 Sensor component 12 Heating element 13 Temperature sensor 14 Bracket 15 Sensor 16 Electronics 17 Fastening element 18 spacers 19 Nozzle opening 20 Deposit 21 open space 22 carriers 23 outer wall 24 Cooling device 25 Admission 26 Outlet 27 Interruption 28 Temperature sensor d distance A Longitudinal axis

Claims

[1] Sensor component (11) for detecting deposits (20) of injection molding material on an injection molding machine (1), comprising a holder (14) and one or more sensors (15) arranged on or in the holder (14), wherein the holder (14) is designed to be arranged at a defined distance (d) from an outer wall (23) of an injection molding machine (1), comprising one or more spacers (18) for holding the holder (14) at the defined distance (d) from the outer wall (23), wherein the one or more spacers (18) are designed as springs. [2] Sensor component (11) according to claim 1, wherein the springs are designed as spiral springs. [3] Sensor component (11) according to one of the preceding claims, comprising a fastening element (17) for fastening the holder (14) to the outer wall (23). [4] Sensor component (11) according to claim 3, wherein the fastening element (17) is designed as a clamping ring. [5] Sensor component (11) according to one of the preceding claims, in which at least one of the sensors (15) is designed as a temperature sensor, optical sensor and / or camera. [6] Sensor component (11) according to one of the preceding claims, wherein the sensors (15) are designed to detect deposits (20) in one or more directions relative to a longitudinal axis (A). [7] Sensor component (11) according to one of the preceding claims, in which the holder (14) is designed to be circumferential or partially circumferential. [8] Sensor component (11) according to one of the preceding claims, comprising a cooling device (24) for cooling one or more components of the sensor component (11). [9] Injection molding machine (1) with the sensor component (11) according to one of the preceding claims, wherein the injection molding machine (1) has an outer wall (23) around which the holder (14) is arranged. [10] Injection molding machine (1) according to claim 9, comprising an injection nozzle (2) and a cylinder (4) in which injection molding material is melted and propelled, wherein the holder (14) is arranged on the injection nozzle, on the cylinder (4) or on a component between the injection nozzle (2) and the cylinder (4). [11] Method for detecting a deposit (20) of injection molding material on an injection molding machine (1), wherein an injection molding machine (1) according to one of claims 9 or 10 is provided and, during operation, the formation of deposits (20) is monitored by means of the one or more sensors (15).

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