Plasticizing and injection device for the production of injection-molded components

Abstract

The invention relates to a plasticizing and injection device (1) and a plasticizing and injection method for producing injection-molded components from a solid molding compound (50), comprising a plasticizing device (2) for plasticizing the solid molding compound (50) into a plasticized injection compound (51), an injection device (6) coupled downstream of the plasticizing device for injecting the plasticized injection compound into a mold cavity (80) of a molding device (8) for molding the injection-molded component, wherein the injection device (6) has a positive displacement pump (60) for injecting a predetermined amount of the injection compound at a predetermined injection volume flow into the molding device (8). The fill level of the mold cavity (80) is used to control and / or regulate the positive displacement pump.

Description

[0001] The invention relates to a plasticizing and injection device and a plasticizing and injection method for producing injection-molded components.

[0002] It is generally known from the prior art that, for the production of injection-molded components, a solid plastic molding compound is first plasticized and then injected into a mold cavity using an injection device. After the plasticized plastic compound has hardened, the mold cavity is opened, and the manufactured and cured injection-molded component can be removed from the mold cavity.

[0003] Gear pumps are also used to ensure precise feeding of the plasticized plastic melt, ensuring a precise volume flow of plasticized plastic mass into the mold cavity.

[0004] In this case, precise control of the plasticizing device with the injection device in the form of the gear pump must be observed.

[0005] DE4331209A1 describes a method for the cyclic injection molding of molded parts by means of a device for producing injection molded parts from molding compound, consisting of a screw cylinder with a conveyor screw for plasticizing the molding compound, an injection device and a mold in which the molding compound is then polymerized or crosslinked, wherein the injection of the molding compound is carried out intermittently or with a time-variable material throughput by means of a gear pump, wherein the plasticizing is carried out with an essentially constant throughput over the entire work cycle, consisting of injecting the molding compound into the mold and subsequent crosslinking or, if necessary, demolding.

[0006] US5863485A describes a method and apparatus for synchronizing the flow of molten polymer or similar materials in molding systems that use manifolds to direct the flow into one or more cavities of an injection mold. The apparatus utilizes intermeshing, interconnected positive displacement pumps, similar to gear pumps in hydraulic systems. These positive displacement pumps are placed in each parallel flow channel so that the entire flow in each channel passes through a gear mechanism.

[0007] From the methods and devices mentioned as examples, it is known to convey and inject plasticized polymer melt into a mold cavity by means of external gear pumps.

[0008] When injecting the plasticized molding compound at a predetermined temperature, the plasticized molding compound may cool down too quickly in the mold cavity.

[0009] This cooling can lead to a shrinkage of the molding compound, resulting in a molded part that does not meet the desired quality requirements.

[0010] Additionally, this results in an uneven mass distribution, especially when the molding compound is injected into multiple mold cavities simultaneously, which in turn can lead to different volume shrinkage in the respective mold cavities. The result is different weights and dimensions of the injection-molded components, which do not meet the desired quality requirements.

[0011] In addition, this shrinkage and uneven mass distribution can lead to greater material consumption.

[0012] It is therefore an object of the invention to provide a plasticizing and injection device or a plasticizing and injection method with which the above-mentioned problems can be prevented and / or at least reduced.

[0013] The object is achieved with regard to the plasticizing and injection device with a plasticizing and injection device having the features according to claim 1.

[0014] According to one aspect of the invention, a plasticizing and injection device for producing injection-molded components from a solid molding compound is provided, comprising a plasticizing device for plasticizing the solid molding compound into a plasticized injection compound, an injection device coupled downstream of the plasticizing device for injecting the plasticized injection compound into a mold cavity of a molding device for molding the injection-molded component, wherein the injection device has a positive displacement pump for injecting a predetermined amount of the injection compound with a predetermined injection volume into the molding device. The degree of filling of the mold cavity is used to control and / or regulate the positive displacement pump.

[0015] By controlling or regulating the positive displacement pump based on the fill level of the mold cavity, volume fluctuations of the plasticizing injection compound cooling in the mold cavity can be compensated for. This allows for more precise regulation of fluctuations in the volume of the plasticized injection compound, and appropriate countermeasures can be implemented in the plasticizing and injection device. This offers the advantage of enabling more precise production of injection-molded components and also requiring less molding compound to be plasticized, since only the required amount of molding compound is plasticized and injected, thus ensuring high quality and dimensional accuracy of the injection-molded components to be produced.

[0016] This is particularly necessary for very small injection-molded components, which are also used in electrical engineering.

[0017] According to one embodiment of the plasticizing and injection device, the degree of filling of the mold cavity can be determined based on pressure and / or volume, wherein the degree of filling is determined successively in a first phase during injection of the plasticized injection mass and in a second phase during pressure build-up in the mold cavity, wherein the degree of filling in the first phase and / or the second phase can be determined based on the injection volume flow of the positive displacement pump and / or the pressure in the mold cavity.

[0018] The degree of filling of the mold cavity in the plasticizing and injection device can be determined successively in a first phase, which can also be referred to as the pre-pressure phase, and in a second phase, which can also be referred to as the holding pressure phase, in each case at least in the first and / or the second phase by determining a pressure in the mold cavity and / or a volume flow towards the mold cavity.

[0019] In the case of volume flow measurement, this is particularly possible because the positive displacement pump has a predeterminable injection volume that can be determined without additional sensors.

[0020] When determining the filling level of the mold cavity by means of pressure, an additional corresponding pressure sensor is advantageously required, which is arranged at a suitable position in the plasticizing and injection device so that the pressure build-up in the mold cavity can be tracked.

[0021] According to a further embodiment of the plasticizing and injection device, the pressure in the mold cavity can be determined by means of a pressure sensor at the outlet of the positive displacement pump.

[0022] This offers the advantage of allowing precise pressure measurement in the mold cavity. This does not require the pressure sensor to be located directly adjacent to the mold cavity, but rather at a sufficient distance, preferably at the outlet of the positive displacement pump.

[0023] The pressure sensor can also be positioned at other locations adjacent to the mold cavity. The key here is that the pressure in the mold cavity can be determined easily and without effort.

[0024] The outlet of the positive displacement pump refers in particular to the mouth area of ​​the positive displacement pump, through which the plasticized molding compound is fed to the mold cavity.

[0025] Positions adjacent to the outlet and / or corresponding supply lines on the positive displacement pump are also conceivable, with the pressure sensor being attached to the supply lines in such a way that the volume flow is not interrupted, blocked and / or disturbed.

[0026] According to another embodiment of the plasticizing and injection device, the pressure sensor for detecting the pressure in the mold cavity and / or a temperature sensor for detecting the temperature of the plasticized injection mass is mounted in a sensor carrier plate, wherein the sensor carrier plate is arranged adjacent to the mold cavity.

[0027] For optimal and accurate pressure and temperature measurement, a sensor carrier plate can be provided in the plasticizing and injection device. This allows for easy and cost-effective retrofitting, retrofitting, and / or replacement of the respective pressure and temperature sensors, allowing for more precise measurement of the required data if necessary.

[0028] According to a further embodiment of the plasticizing and injection device, a hot runner device for tempering the plasticized injection mass is positioned between the plasticizing and injection device and the molding device, so that the plasticized injection mass can be provided with a predetermined mass temperature, wherein the hot runner device for tempering the plasticized injection device has a heating device and / or a cooling device.

[0029] With the additional hot runner device for tempering the plasticized injection mass, it is possible to keep the plasticized injection mass at a predetermined temperature over a predetermined time, or to temper it accordingly in such a way that a reduction in volume due to cooling in the mold cavity can be balanced, compensated and / or changed.

[0030] To ensure that the predetermined temperature of the plasticized injection mass does not exceed or fall below an upper or lower limit, the heating device optionally has both a heating device and a cooling device.

[0031] According to another embodiment of the plasticizing and injection device, the injection device is positioned between the plasticizing device and the hot runner device and / or the injection device is positioned between the hot runner device and the molding device, wherein a gate is positioned between the injection device and the mold cavity for uniformly injecting the injection compound into the mold cavity, the shape of which gate is adaptable based on the properties of the material of the molding compound.

[0032] Depending on the material used, the hot runner device can be positioned at predetermined positions between the plasticizing device for plasticizing the molding compound and the injection device for injecting the plasticized molding compound.

[0033] This allows optimal utilization of the plasticizing and injection device properties with the respective materials of the molding compound and their associated properties.

[0034] Furthermore, a gate for uniform injection into the mold cavity is adaptable in such a way that the area in which the gate can be used is designed in such a way that an associated gate can be exchanged to suit the respective material of the molding compound to be plasticized.

[0035] Optionally, the gate is also designed in the injection device in such a way that its shape can be predetermined accordingly by making corresponding sections of the gate movable and / or deformable.

[0036] The position of the injection device after the plasticizing device and in direct connection to the hot runner device or in direct connection to the mold cavity or gate also has the advantage that the injection process is closer to the mold cavity and can be controlled and regulated more precisely in terms of volume flow and temperature.

[0037] According to a further embodiment of the plasticizing and injection device, the gate is designed as a non-closable free-flow gate and / or is equipped with a closing device, in particular a closing needle, so that the section can be closed at least temporarily.

[0038] The gate is designed to ensure uniform feeding of the plasticized molding compound into the mold cavity.

[0039] In addition, the shape can be adapted to the plasticized molding compound and its properties.

[0040] A closing device may be provided for at least temporarily closing the gate. The closing device may comprise a locking pin.

[0041] Other forms of closure devices may also be provided. For example, a corresponding valve closure and / or a flap may be provided at the feed inlet of the gate.

[0042] This allows for separate maintenance of the respective components of the plasticizing and injection units. Furthermore, the closing device can also be used to at least partially close the gate, allowing the feed rate to be controlled via the gate.

[0043] According to a further embodiment of the plasticizing and injection device, the positive displacement pump comprises a gear pump and / or a multiple gear pump.

[0044] For the precise supply of a predetermined injection volume flow, the positive displacement pump can be a gear pump, preferably an external gear pump, which has a feed gear and a drive gear, wherein the feed gear meshes with the drive gear and interacts in such a way that a feed area is provided with the feed gear and the drive gear, so that with each gear stroke a predetermined amount of plasticized molding compound can be supplied, wherein a particularly advantageous feed can be supplied.

[0045] The positive displacement pump can also be a multiple gear pump, such as a planetary gear pump, an in-line gear pump and / or gear pumps arranged in different planes.

[0046] The gear pump can also be designed as an internal gear pump.

[0047] The object is achieved with regard to the method using a plasticizing and injection method with the features of claim 9.

[0048] According to one aspect of the invention, a plasticizing and injection method for producing injection-molded components from a solid molding compound is provided, wherein the plasticizing and injection device according to at least one of the preceding embodiments is configured to carry out the plasticizing and injection method, wherein the solid molding compound is plasticized into a plasticized injection compound by means of a plasticizing device, wherein the plasticized injection compound is injected into a mold cavity to form an injection-molded part by displacement by means of a positive displacement pump. The fill level of the mold cavity and the detected fill level are used to control and / or regulate the positive displacement pump.

[0049] By detecting and using the fill level to control or regulate the positive displacement pump, the plasticized injection compound can be fed with particular precision in the required quantities. Corresponding changes in shape and volume of the plasticized injection compound in the mold cavity can also be taken into account, as the precise fill level of the mold cavity is detected. This allows, for example, corresponding volume shrinkages due to cooling of the plasticized injection compound in the mold cavity to be immediately taken into account and compensated, ensuring that precisely the quantity required for optimal, high-quality injection-molded components can be fed.

[0050] The process is particularly advantageous for injection-molded components used in microelectronics, as these components have particularly small dimensions but can be manufactured with great precision on a micrometer basis.

[0051] Furthermore, precise measurement of the fill level and readjustment of the positive displacement pump can prevent excessive injection molding compound from being fed into the mold cavity. Therefore, the process also offers environmental benefits, as less molding compound is required and the amount of compound needed for each injection-molded part can be better estimated. Furthermore, the production of low-quality injection-molded components can be reduced and, ideally, completely prevented.

[0052] The position of the injection device close to the mold cavity also has the advantage that lower injection pressures and holding pressures may be required to fill the mold cavity compared to standard injection molding. This has the advantage that machines with smaller mold clamping devices can be used for the same application, which have lower energy consumption and require less space.

[0053] According to one embodiment of the plasticizing and injection process, the degree of filling of the mold cavity is determined successively in a first phase in which the plasticized injection mass is introduced into the mold cavity and in a second phase in which the plasticized injection mass introduced into the mold cavity builds up pressure.

[0054] The cavity fill level is determined in two different phases, allowing for precise determination of the cavity fill level. By performing these sequential phases, which can also be referred to as the pre-pressure phase, injection phase, or holding pressure phase, it is possible to determine the cavity fill level very precisely.

[0055] This allows for better control of the feed of the plasticized molding compound into the mold cavity, ensuring that the mold cavity is optimally and reproducibly filled with the plasticized injection compound. Furthermore, overfilling of the mold cavity with too much plasticized injection compound can be prevented.

[0056] According to a further embodiment of the plasticizing and injection process, in the first phase the degree of filling is determined by means of the injection volume flow and / or the pressure and / or in the second phase the degree of filling of the mold cavity is determined based on the pressure determined in the mold cavity and / or by means of the injection volume.

[0057] To determine the filling pressure of the not yet fully filled mold cavity in the first phase, also known as the pre-pressure phase, the injection volume in the positive displacement pump is preferably used, since this value is known. The volume of the mold cavity is also known. At the same time, the injection volume flow and the known volume make it easy to determine when and after how much injection volume the filling level of the mold cavity is reached.

[0058] Alternatively, this can also be determined by pressure buildup, both in the first and second phases. As soon as pressure builds up in the mold cavity, it can be concluded that the cavity fill level has been reached. The pressure can then be used to regulate and / or control the positive displacement pump. The same applies to the injection volume, which is known from the positive displacement pump used. This can also be used to determine the cavity fill level in the first or second phase.

[0059] Preferably, in the first phase, the degree of filling of the mold cavity is determined by means of the injection volume and in the second phase, when pressure builds up in the mold cavity, the degree of filling of the mold cavity is determined by means of the ascertainable pressure.

[0060] According to a further embodiment of the plasticizing and injection method, the control of the positive displacement pump is controlled based on the supplied injection volume and / or the control of the positive displacement pump is controlled based on the determined pressure, or vice versa, wherein the speed of the positive displacement pump is controlled and / or regulated in the first phase and is controlled and / or regulated in the second phase.

[0061] The known or determined injection volume can ideally be used to control the positive displacement pump. Furthermore, the determined pressure can be used to control the positive displacement pump. Both are also necessary for closed-loop control, whereby control is performed based on recorded sensor data.

[0062] Control is understood here as controlling the drive of the positive displacement pump, whereby control is carried out without predetermined acquisition of sensor data.

[0063] When controlling the positive displacement pump, data from sensors is also taken into account so that the actual state is determined and the positive displacement pump can be controlled accordingly.

[0064] A control of the positive displacement pump or its speed in the first phase is preferred, and a regulation of the positive displacement pump, in particular its speed in the second phase is preferred.

[0065] The control can be carried out using determined data, such as pressure and / or known data such as the injection volume flow.

[0066] According to a further embodiment of the plasticizing and injection process, when the mold cavity is volumetrically filled, the injection volume flow is controlled based on the internal pressure.

[0067] The mold cavity is considered volumetrically filled when the injection volume flow has filled the mathematically calculable volume of the mold cavity.

[0068] Once this point in time or volume filling is reached, the recording of the pressure building up in the mold cavity begins.

[0069] Based on the measured pressure of the mold cavity, the positive displacement pump and its speed are then controlled.

[0070] According to a further embodiment of the plasticizing and injection process, the first filling level corresponds to a filling level of the mold cavity of 75% to 100%, while the second filling level corresponds to a filling level of the mold cavity of 95% to 100%.

[0071] Depending on the molding compound used, the control and regulation ranges for the first and second filling levels may be different, which also applies to the first and second phases, in order to ensure optimal control and regulation of the positive displacement pump and to ensure optimal filling of the mold cavity.

[0072] According to a further embodiment of the plasticizing and injection method, the plasticized injection mass is provided with a predetermined measuring temperature by tempering the plasticized injection mass, wherein the temperature and / or pressure of the plasticized injection mass is recorded during injection.

[0073] In addition to the control and regulation of the positive displacement pump, the temperature of the plasticized injection mass can also be recorded and measured for optimal filling.

[0074] In order to ensure an optimal temperature of the plasticized injection mass, tempering is possible using appropriate heating devices provided at the access area of ​​the mold cavity.

[0075] Appropriate heaters can also be provided on the mold cavity so that a change in volume due to cooling in the mold cavity can be prevented or at least reduced.

[0076] According to a further embodiment of the plasticizing and injection method, a speed of an extruder shaft of the plasticizing device and / or a speed of the positive displacement pump of the injection device is regulated and / or controlled based on the detected temperature, the detected injection volume and / or the detected pressure.

[0077] By collecting multiple data based on theoretically predetermined values ​​and collected data sensors, optimal control of both the plasticizing device and the injection device can be performed.

[0078] The recorded data is used to control the extruder shaft of the plasticizing device and / or the positive displacement pump, in particular to regulate and control the respective speeds.

[0079] According to a further embodiment of the plasticizing and injection process, the temperature control of the heating channel device is regulated and / or controlled based on the detected temperature, the detected injection volume and / or the detected pressure.

[0080] In addition to the regulation and control of the speed of the plasticizing and / or injection device, the known or recorded data can also be used to control and regulate the heating channel device, so that the plasticized injection mass can always be introduced into the mold cavity in an optimal condition.

[0081] Advantageous embodiments and further developments of the invention are described in the illustrated embodiments or will become apparent below together with the description of the preferred embodiments of the invention with reference to the figures.

[0082] They represent: Fig. 1 A schematic partial sectional view of a first embodiment of the plasticizing and injection device according to the invention with a plasticizing device, a hot runner device, an injection device and a molding device for plasticizing and injecting a molding compound into an injection-molded component, Fig. 2 a schematic partial view of an embodiment of the injection device, the hot runner device and the molding device, Fig. 3 a schematic detailed view of another embodiment of the injection device, the hot runner device and the molding device, Fig. 4 a schematic detailed view of another embodiment of the injection device together with the molding device, Fig. 5 a schematic partial view of a further embodiment of the plasticizing and injection device according to the invention, Fig. 6 a graph showing the pressure curve and the injection volume flow curve over time in a first phase and in a second phase during injection into the molding device, and Fig. 7 a schematic block diagram of process steps of the plasticizing and injection process according to the invention

[0083] Fig. 1 shows a schematic partial sectional view of a first embodiment of a plasticizing and injection device 1 according to the invention with a plasticizing device 2, a hot runner device 4, an injection device 6 and a molding device 8. The plasticizing device 2 is designed to plasticize a molding compound 50 to form a plasticized injection compound 51.

[0084] For this purpose, the plasticizing device 2 has an extruder screw 21 with a predetermined external thread, which is positioned in an extruder housing 22 and is driven to rotate around its center of gravity by means of an extruder drive 20.

[0085] The molding compound 50 to be plasticized is provided in a molding compound feed container 23, via which the plastic chips of the molding compound 50 to be plasticized can be guided to the extruder screw 21.

[0086] The molding compound 50 is ground by the extruder screw 21 and its external thread in such a way that the molding compound 50, which usually comprises solid plastic chips, is ground into a plasticized injection compound 51, which can be formed into an injection-molded component.

[0087] The production of an injection-molded component then takes place in a tool closing device 3.

[0088] The tool closing device 3 is coupled to the outlet opening of the plasticizing device 2 so that the plasticized injection mass 51 can be introduced into a mold cavity 80.

[0089] The tool closing device 3 has in the Fig. 1, the molding machine has a stationary clamping panel 12 on which a hot runner device 4 is mounted for tempering and feeding the plasticized injection mass 51 to the mold cavity 80 of the molding device 8.

[0090] An injection device 6 is provided between the hot runner device 4 and the molding device 8. Sensor carrier plates 9 are provided on both sides of the injection device 6, in which sensors, such as temperature sensors 92 and / or pressure sensors 91, can be mounted (see also Fig. 4 and Fig. 5), wherein a sensor carrier plate 9 is arranged on the hot side 40 of the hot runner device 4.

[0091] For access to the mold cavity 80, the mold device 8 is mounted on a movable clamping panel 14, which allows at least a reciprocating movement of the mold device 8 from the sensor plate 9, indicated in Fig. 1 with a double arrow so that the injection-molded component formed in the mold cavity 80 can be removed.

[0092] Optionally, a so-called gate 99 can be provided at the feed opening of the mold cavity 80 for feeding the plasticized injection mass 51, via which gate the injection of the plasticized injection mass 51 into the mold cavity 80 can be improved and adapted to the respective properties of the injection mass 51.

[0093] For example, the gate 99 may have a predetermined shape that improves injection of the plasticized injection compound 51 into the mold cavity 80, wherein the gate 99 may have a corresponding nozzle shape.

[0094] The plasticized injection compound 51 can be injected into the mold cavity 80 by means of the injection device 6. For this purpose, the injection device 6 has a positive displacement pump 60. The positive displacement pump 60 enables a precise and optimal supply of an injection volume flow Vinj into the mold cavity 80.

[0095] Fig. 2 shows an embodiment of the tool closing device 3. On the Fig. In the embodiment of the tool closing device 3 shown in Figure 2, the hot runner device 4 and the associated hot runner 43 are connected directly adjacent to the positive displacement pump 60, which introduces the injection material 51 plasticized by the plasticizing device 2 into the mold cavity 80 via a gate 99.

[0096] In the Fig. 2, the regulation or control of the displacement pump 60 takes place exclusively via the injection volume Vinj. Advantageously, in this embodiment, additional sensors, such as a temperature sensor and a pressure sensor, can be dispensed with, which are preferably mounted in the sensor carrier plate 9, as for example in Fig. 5 shown.

[0097] In the Fig. In the embodiment shown in Figure 3, the arrangement and sequence of the injection device 6 and the hot runner device 4 in the plasticizing conveying direction 100 is exchanged.

[0098] After the Fig. In the embodiment shown in Figure 3, the injection device 6 is adjacent to the plasticizing device 2 or the associated stationary clamping panel 12. The plasticized injection mass 51 is first conveyed via the positive displacement pump 60 into the hot runner device 4, which then supplies further mold cavities 80 via corresponding hot runners 43.

[0099] The mouth of the hot runners 43 can each be provided with a gate 99, based on the properties to be processed of the molding compound 50 to be plasticized and injected.

[0100] Fig. 4 shows a further embodiment of the tool closing device 3. In the Fig. In the embodiment shown in Figure 4, the sensor plate 9 with an associated temperature sensor 92 or pressure sensor 91 is arranged adjacent to the mold cavity 80 of the molding device 8. On the opposite side of the sensor carrier plate 9, the hot runner device 4 is provided, in which the injection device 6 is mounted, such that the hot runner device 4 surrounds the injection device 6 at least in sections.

[0101] In addition, the gate 99 has a closing device 98. The closing device 98 can, for example, be a shut-off needle 98, with which the access and supply of plasticized injection compound into the mold cavity 80 can be blocked.

[0102] In Fig. 5 shows another embodiment of the plasticizing and injection device. The main difference to the Fig. The exemplary embodiment of the plasticizing and injection device 1 shown in Figure 1 is that the positive displacement pump 60 comprises multiple pumps as a positive displacement pump. The multiple pump of the positive displacement pump 60 can be a planetary gear, gear pumps coupled in series and / or in planes one above the other, so that a plurality of mold cavities 80 can be supplied via a corresponding number of hot runners 43.

[0103] An example is Fig. 5 shows a hot runner 43 which has additional branches for the respective mold cavity 80. In addition, pressure sensors 91 are arranged in the sensor carrier plate 9 on both sides above and below the hot runner 43 or on opposite sides in each sensor carrier plate 9.

[0104] Furthermore, the controller 10 controls both the extruder drive 20, EA and the pump drive PA, so that the extruder drive 20 and the pump drive PA can be optimally adjusted and controlled to one another.

[0105] Fig. 6 shows a graph illustrating the pressure curve in the mold cavity 80 during injection of the plasticized injection mass 51 over time in combination with the rotational speed rpm and the injection volume Vinj.

[0106] The time t is given on the abscissa t and the pressure P and the speed rpm are given on the ordinate axes.

[0107] The pressure curve p indicates the pressure p in the mold cavity 80. The time axis t is divided into a first phase P1, also called the pre-pressure phase, and a second phase P2, also called the holding pressure phase. The end of the first phase P1 and the beginning of the second phase P2 are determined by the fill level of the mold cavity 80. For the fill level of the mold cavity 80, for example, the injection volume Vinj and / or the pressure p building up in the mold cavity 80 can be used.

[0108] In the first phase P1 or the pre-pressure phase P1, the injection volume Vinj increases continuously over a predetermined time t, then remains constant and is reduced linearly to a predetermined amount when the predetermined filling level in the mold cavity is reached and is only reduced to a smaller amount in the holding pressure phase, as in Fig. 6. The time span in the graph of Fig. 6 of the first phase P1 is smaller than the time span of the second phase P2.

[0109] The determined injection volume Vinj and the determined pressure p can be used to control, in particular, the speed of the displacement pump 60. In the Fig. In the embodiment shown in Figure 6, in the first phase P1, the fill level is calculated using the injection volume Vinj. The volume of the mold cavity 80 and the value of the injection volume Vinj of the positive displacement pump 60 are known through a predetermined speed. This allows control of the speed RPM of the positive displacement pump 60.

[0110] When a predetermined filling level is reached, which can be in the range of 95% to 100% of the volumetric volume of the mold cavity 80, the speed of the displacement pump 60 is regulated in the second phase P2 based on the determined pressure p, so that exactly the required amount of plasticized injection compound 51 can be injected into the mold cavity 88 with the displacement pump 60.

[0111] However, other control or regulation combinations are also possible in the first phase P1 and the second phase P2. For example, in the first phase P1 and the second phase P2, the speed of the positive displacement pump can be controlled solely based on the injection volume Vinj. Additionally or alternatively, the control can also be controlled in the first phase P1 based on the determined pressure p in the mold cavity 88.

[0112] In particular, sensor data from pressure sensors and / or temperature sensors are used in the control so that optimal control of the pump speed can be carried out based on data determined by sensors.

[0113] Fig. 7 shows a schematic block diagram of an embodiment of process steps of the plasticizing and injection process according to the invention.

[0114] In step S1, a solid molding compound 50 is plasticized into a plasticized injection compound 51 by means of the plasticizing device 2. The plasticized injection compound 51 is injected into a mold cavity to form an injection-molded component in step S2 by displacement using a positive displacement pump. The fill level of the mold cavity is detected, and the detected fill level is used to control and regulate the positive displacement pump 60 in step S3.

[0115] In step S4, in a first phase P1, also called the pre-pressure phase or injection phase, the fill level of the mold cavity 80 is recorded. In a second phase P2, in a step S5, the fill level of the mold cavity 80 is recorded again, wherein here, particularly preferably, an additional parameter such as the pressure p building up in the mold cavity 80 is also determined at the same time. In step S4, in the first phase, the fill level of the mold cavity 80 can be determined by the injection volume Vinj of the positive displacement pump 60 and / or by the pressure measured in the mold cavity 80. Both are used to control or regulate the speed of the positive displacement pump.

[0116] In the second phase P2 in step S5, the filling degree of the mold cavity can alternatively be determined by the pressure and / or by the determined injection volume Vinj and / or by a combination of the two parameters.

[0117] In steps S6 and S7, it is determined when the first phase P1 is completed and the second phase P2 begins. This can be determined, for example, by the first phase P1 being completed when the mold cavity 80 is volumetrically filled. Volumetric filling refers to a calculated filling of the volume of the mold cavity 80 based on the known injection volume Vinj.

[0118] In step S7, the positive displacement pump 60 is then controlled or regulated based on the injection volume Vinj and / or depending on the material used as the molding compound 50. Depending on the molding compound 50 used, closed-loop control may be required in both the first phase P1 and the second phase P2. However, pure open-loop control in both phases P1 and P2 may also be sufficient.

[0119] Preferably, first, the positive displacement pump 60 or its speed is controlled in the first phase P1 and, in the second phase P2, the speed of the positive displacement pump 60 is regulated based on a detected parameter such as pressure, temperature and / or injection volume by respective associated sensors.

[0120] To determine limit values ​​for the fill level of the mold cavity 80, the first fill level in the first phase of the mold cavity 80 can be 75% to 100% of the volume of the mold cavity 80, and the second fill level in the second phase of the mold cavity can be 95% to 100%. Furthermore, the temperature of the injection mass 51 can be determined using corresponding temperature sensors 92 in the sensor carrier plate 9, with the detected measurement temperature MT being used to temper the injection mass in the hot runner device 4.

[0121] In particular, the heating device 41 or the cooling device 41 of the hot runner device 4 can be controlled by means of the determined measuring temperatures MT of the plasticized injection mass 51.

[0122] In addition, for the control of the hot runner device 4, the hot runner device 4 can be controlled or regulated using the determined injection volume Vinj, the detected pressure p and / or the detected temperature MT.

[0123] An embodiment in which particularly few sensors are used is preferred. However, for certain properties of the molding compound 50 used, it may be necessary to provide both a pressure sensor 91 and a temperature sensor 92, so that precise production of the injection-molded component is possible using the plasticizing and injection method according to the invention. List of reference symbols 1 plasticizing and injection device 2 plasticizing device 3 Tool closing device 20 Extruder drive (EA) 21 Extruder screw 22 extruder housing 23 molding compound feed tanks 4 Hot runner device 40 Hot Side 41 Heating device 42 Cooling device 43 hot runner 6 Injection device 60 positive displacement pump 8 Forming device 80 mold cavity 81 Mouth entrance 9 Sensor carrier plate 90 data line 91 Pressure sensor 92 Temperature sensor 98 locking device 99 Temperature increase device gate 10 Control (CU) 12 stationary support frame fixed clamping plate 14 movable support frame Movable clamping plate 50 molding compound 51 Plasticized injection mass 100 Plasticizing conveyor direction PA pump drive CU Control Unit, control EA extruder drive p pressure curve, pressure P1, P2 first phase, second phase rpm speed (revolutions per minute) Vinj injection volume, injection volume flow QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 4331209A1

[0005] US 5863485A

[0006]

Claims

[1] Plasticizing and injection device (1) for producing injection-molded components from a solid molding compound (50), comprising a plasticizing device (2) for plasticizing the solid molding compound (50) into a plasticized injection compound (51), an injection device (6) coupled to the plasticizing device for injecting the plasticized injection compound into a mold cavity (80) of a molding device (8) for molding the injection-molded component, wherein the injection device (6) has a positive displacement pump (60) for injecting a predetermined amount of the injection compound with a predetermined injection volume flow into the molding device (8), characterized by that the filling level of the mold cavity (80) is used to control and / or regulate the positive displacement pump (60). [2] Plasticizing and injection device according to claim 1, characterized bythat the degree of filling of the mold cavity can be determined on a pressure-based and / or volume-based basis, wherein the degree of filling of the mold cavity is determined successively in a first phase (P1) during injection of the plasticized injection mass (51) and in a second phase (P2) during pressure build-up in the mold cavity, wherein the degree of filling in the first phase and / or the second phase can be determined based on the injection volume flow of the positive displacement pump and / or the pressure (p) in the mold cavity. [3] Plasticizing and injection device according to at least one of the preceding claims 1 or 2, characterized by that the pressure (p) in the mold cavity can be determined by means of a pressure sensor (91) at the outlet of the displacement pump (60). [4] Plasticizing and injection device according to at least one of the preceding claims, characterized bythat the pressure sensor for detecting the pressure in the mold cavity and / or a temperature sensor (92) for detecting the temperature of the plasticized injection mass is mounted in a sensor carrier plate, wherein the sensor carrier plate is arranged adjacent to the mold cavity. [5] Plasticizing and injection device according to at least one of the preceding claims, characterized by that a hot runner device (4) for tempering the plasticized injection mass (51) is positioned between the plasticizing device (2) and the molding device (8), so that the plasticized injection mass can be provided with a predetermined mass temperature (MT), wherein the hot runner device (4) has a heating device (41) and / or a cooling device (42) for tempering the plasticized injection mass (51). [6] Plasticizing and injection device according to at least one of the preceding claims, characterized bythat the injection device (6) is positioned between the plasticizing device (2) and the hot runner device (4) and / or the injection device (6) is positioned between the hot runner device (4) and the molding device (8), wherein a gate (99) for uniformly injecting the injection compound (51) into the molding cavity (80) is positioned between the injection device (6) and the mold cavity, the shape of which gate is adaptable based on the properties of the material of the molding compound. [7] Plasticizing and injection device according to at least one of the preceding claims, characterized by that the gate (99) is designed as a non-closable free-flow gate (99) and / or is equipped with a closing device, in particular in the form of a closing needle, so that the gate can be closed at least temporarily. [8] Plasticizing and injection device according to at least one of the preceding claims, characterized by that the positive displacement pump comprises a gear pump and / or a multiple gear pump. [9] Plasticizing and injection method for producing injection-molded components from a solid molding compound (50), wherein the plasticizing and injection device (1) according to at least one of the preceding claims 1 to 8 is set up to carry out the plasticizing and injection method, wherein the solid molding compound is plasticized by means of a plasticizing device into a plasticized injection compound (51) (S1), wherein the plasticized injection compound (51) is injected into an injection-molded component by displacement by means of a displacement pump into a mold cavity (80) (S2), characterized by that the filling level of the mold cavity is recorded and the recorded filling level is used to control and / or regulate the positive displacement pump. [10] Plasticizing and injection method according to claim 9 characterized bythat the degree of filling of the mold cavity is determined successively in a first phase in which the plasticized injection mass is introduced into the mold cavity and in a second phase in which the plasticized injection mass introduced into the mold cavity builds up pressure. [11] Plasticizing and injection process according to at least one of the preceding claims 9 or 10, characterized by that in the first phase the degree of filling is determined by means of the injection volume flow and / or the pressure and / or that in the second phase the degree of filling of the mold cavity is determined based on the pressure determined in the mold cavity and / or by means of the injection volume flow. [12] Plasticizing and injection process according to at least one of the preceding claims 9 to 11, characterized bythat the control of the positive displacement pump is controlled based on the supplied injection volume flow and / or a control of the positive displacement pump is controlled based on the determined pressure, or vice versa, wherein the speed of the positive displacement pump (60) is controlled and / or regulated in the first phase and controlled and / or regulated in the second phase. [13] Plasticizing and injection process according to at least one of the preceding claims 9 to 12, characterized by that when the mold cavity is volumetrically filled, the injection volume flow is controlled based on the internal pressure. [14] Plasticizing and injection process according to at least one of the preceding claims 9 to 13, characterized by that in the first phase (P1) the filling level corresponds to a filling level of the mold cavity of 75% to 100%, whereas in the second phase (P2) the filling level corresponds to a filling level of the mold cavity of 95% to 100%. [15] Plasticizing and injection process according to at least one of the preceding claims 9 to 14, characterized by that the plasticized injection mass (51) is provided with a predetermined mass temperature (MT) by tempering the plasticized injection mass, wherein the temperature and / or the pressure of the plasticized injection mass is detected (S5) during injection (S4). [16] Plasticizing and injection process according to at least one of the preceding claims 9 to 15, characterized by that based on the detected temperature, the detected injection volume flow and / or the detected pressure, a speed of an extruder shaft (21) of the plasticizing device (2) and / or a speed of the positive displacement pump (60) of the injection device (6) is regulated and / or controlled. [17] Plasticizing and injection process according to at least one of the preceding claims 9 to 16, characterized bythat based on the detected temperature, the detected injection volume flow and / or the detected pressure, a tempering of the hot runner device (4) is regulated and / or controlled.

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